Provided by: xboard_4.4.2-1_i386 bug

NAME

       xboard - X graphical user interface for chess

SYNOPSIS

       xboard [options]
       xboard -ics -icshost hostname [options]
       xboard -ncp [options]
       |pxboard
       cmail [options]

DESCRIPTION

       XBoard  is a graphical chessboard that can serve as a user interface to
       chess  engines  (such  as  GNU  Chess),  the  Internet  Chess  Servers,
       electronic  mail  correspondence chess, or your own collection of saved
       games.

       This manual documents version 4.4.2 of XBoard.

MAJOR MODES

       XBoard always runs in one of four major modes.  You  select  the  major
       mode from the command line when you start up XBoard.

       xboard [options]
              As  an interface to GNU Chess or another chess engine running on
              your machine, XBoard lets you play a game against  the  machine,
              set  up  arbitrary  positions,  force  variations,  watch a game
              between two chess engines,  interactively  analyze  your  stored
              games or set up and analyze arbitrary positions.  (Note: Not all
              chess engines support analysis.)

       xboard -ics -icshost hostname [options]
              As Internet Chess Server (ICS) interface, XBoard lets  you  play
              against  other  ICS  users,  observe  games they are playing, or
              review games that have  recently  finished.   Most  of  the  ICS
              "wild" chess variants are supported, including bughouse.

       xboard -ncp [options]
              XBoard  can  also  be used simply as an electronic chessboard to
              play through games. It will read and write game files and  allow
              you  to  play  through  variations  manually.  You can use it to
              browse games off the net or review games you have saved.   These
              features are also available in the other modes.

       |pxboard
              If  you  want  to pipe games into XBoard, use the supplied shell
              script ‘pxboard’.  For example, from the news reader ‘xrn’, find
              a  message  with one or more games in it, click the Save button,
              and type ‘|pxboard’ as the file name.

       cmail [options]
              As an interface to electronic mail correspondence chess,  XBoard
              works  with the cmail program. See CMail below for instructions.

MENUS, BUTTONS, AND KEYS

       To move a piece, you can drag it with the left mouse button, or you can
       click  the  left  mouse button once on the piece, then once more on the
       destination square.  To drop a new piece on a square (when applicable),
       press  the  middle or the right mouse button over the square and select
       from the pop-up menu.  In cases where you can drop either  a  white  or
       black  piece,  use the middle button (or shift+right) for white and the
       right button (or shift+middle) for  black.   When  you  are  playing  a
       bughouse  game  on  an  Internet  Chess Server, a list of the off-board
       pieces that each player has available is  shown  in  the  window  title
       after  the  player’s name; in addition, the piece menus show the number
       of pieces available of each type. From version 4.3.14 on,  it  is  also
       possible in crazyhouse, bughouse or shogi to dag and drop pieces to the
       board from the holdings squares displayed next to the board.

       All other XBoard commands are available from the  menu  bar.  The  most
       frequently  used commands also have shortcut keys or on-screen buttons.

       When XBoard is iconized, its graphical icon is a white knight if it  is
       White’s  turn  to  move,  a  black  knight  if it is Black’s turn.  See
       Iconize in Keys below if you have  problems  getting  this  feature  to
       work.

   File Menu
       New Game
              Resets  XBoard  and  the  chess engine to the beginning of a new
              chess game. The ‘r’ key is a keyboard  equivalent.  In  Internet
              Chess  Server  mode,  clears  the  current state of XBoard, then
              resynchronizes with the ICS by sending a refresh command. If you
              want  to  stop playing, observing, or examining an ICS game, use
              an appropriate command from the Action  menu,  not  ‘New  Game’.
              See Action Menu.

       New Shuffle Game
              Similar  to  ‘New  Game’, but allows you to specify a particular
              initial position (according to a standardized numbering  system)
              in  chess  variants which use randomized opening positions (e.g.
              Chess960).  The selected opening position will  persistently  be
              chosen on any following New Game command until you use this menu
              to select another. Selecting position number -1 will  produce  a
              newly randomized position on any new game.  Using this menu item
              in variants that normally do not shuffle their opening  position
              does  cause  these variants to become shuffle variants until you
              use the  ‘New  Shuffle  Game’  menu  to  explicitly  switch  the
              randomization off, or select a new variant.

       New Variant
              Allows  you  to select a new chess variant in non-ICS mode.  (In
              ICS play, the ICS is responsible for deciding which variant will
              be played, and XBoard adapts automatically.) If you play with an
              engine, the engine must be able to play the selected variant, or
              the   command  will  be  ignored.   XBoard  supports  all  major
              variants, such as xiangqi, shogi,  chess,  chess960,  Capablanca
              Chess,  shatranj,  crazyhouse,  bughouse.   (But not every board
              size has built-in bitmaps for un-orthodox pieces!)

       Load Game
              Plays a game from a record file.  The  ‘g’  key  is  a  keyboard
              equivalent.   A  pop-up dialog prompts you for the file name. If
              the file contains more than one game,  a  second  pop-up  dialog
              displays  a list of games (with information drawn from their PGN
              tags,  if  any),  and  you  can  select  the   one   you   want.
              Alternatively,  you  can load the Nth game in the file directly,
              by typing the number ‘N’ after the file  name,  separated  by  a
              space.

              The  game  file parser will accept PGN (portable game notation),
              or in fact almost any file  that  contains  moves  in  algebraic
              notation.   Notation  of  the form ‘P@f7’ is accepted for piece-
              drops in bughouse games; this is a nonstandard extension to PGN.
              If  the  file includes a PGN position (FEN tag), or an old-style
              XBoard position diagram bracketed by ‘[--’ and ‘--]’ before  the
              first move, the game starts from that position. Text enclosed in
              parentheses, square brackets, or curly braces is assumed  to  be
              commentary  and  is displayed in a pop-up window. Any other text
              in the file is ignored. PGN variations (enclosed in parentheses)
              are  treated  as  comments; XBoard is not able to walk variation
              trees.  The nonstandard PGN tag  [Variant  "varname"]  functions
              similarly  to  the  -variant  command-line  option  (see below),
              allowing games in certain chess variants to be loaded.  There is
              also a heuristic to recognize chess variants from the Event tag,
              by looking for the strings that the Internet Chess  Servers  put
              there when saving variant ("wild") games.

       Load Next Game
              Loads  the  next game from the last game record file you loaded.
              The shifted ‘N’ key is a keyboard equivalent.

       Load Previous Game
              Loads the previous game from  the  last  game  record  file  you
              loaded.   The  shifted  ‘P’  key  is a keyboard equivalent.  Not
              available if the last game was loaded from a pipe.

       Reload Same Game
              Reloads the last game you loaded.  Not  available  if  the  last
              game was loaded from a pipe.

       Save Game
              Appends a record of the current game to a file.  A pop-up dialog
              prompts you for the file name. If the game did  not  begin  with
              the  standard  starting  position,  the  game  file includes the
              starting position used. Games are saved  in  the  PGN  (portable
              game  notation)  format, unless the oldSaveStyle option is true,
              in which case they are saved in an older format that is specific
              to XBoard. Both formats are human-readable, and both can be read
              back by the ‘Load Game’ command.  Notation of the form ‘P@f7’ is
              accepted   for   piece-drops   in  bughouse  games;  this  is  a
              nonstandard extension to PGN.

       Copy Game
              Copies a record of the current game to an internal clipboard  in
              PGN  format and sets the X selection to the game text.  The game
              can be pasted to another application (such as a text  editor  or
              another  copy of XBoard) using that application’s paste command.
              In many X applications, such as  xterm  and  emacs,  the  middle
              mouse  button  can  be used for pasting; in XBoard, you must use
              the Paste Game command.

       Paste Game
              Interprets the current X selection as a game  record  and  loads
              it, as with Load Game.

       Load Position
              Sets  up  a  position  from  a  position  file.  A pop-up dialog
              prompts you for the file name. If the file  contains  more  than
              one  saved  position, and you want to load the Nth one, type the
              number N after the file name, separated  by  a  space.  Position
              files  must  be  in  FEN  (Forsythe-Edwards notation), or in the
              format that the Save Position command writes  when  oldSaveStyle
              is turned on.

       Load Next Position
              Loads  the next position from the last position file you loaded.

       Load Previous Position
              Loads the previous position from  the  last  position  file  you
              loaded.   Not  available  if the last position was loaded from a
              pipe.

       Reload Same Position
              Reloads the last position you loaded.  Not available if the last
              position was loaded from a pipe.

       Save Position
              Appends  a  diagram of the current position to a file.  A pop-up
              dialog prompts you for the file name. Positions are saved in FEN
              (Forsythe-Edwards  notation)  format  unless  the ‘oldSaveStyle’
              option is true, in which case they are saved in an older, human-
              readable  format that is specific to XBoard. Both formats can be
              read back by the ‘Load Position’ command.

       Copy Position
              Copies the current position to  an  internal  clipboard  in  FEN
              format  and  sets  the  X  selection  to the position text.  The
              position can be pasted to another application (such  as  a  text
              editor or another copy of XBoard) using that application’s paste
              command.  In many X applications, such as xterm and  emacs,  the
              middle mouse button can be used for pasting; in XBoard, you must
              use the Paste Position command.

       Paste Position
              Interprets the current X selection as a FEN position  and  loads
              it, as with Load Position.

       Mail Move
       Reload CMail Message
              See CMail.

       Exit   Exits from XBoard. The shifted ‘Q’ key is a keyboard equivalent.

   Mode Menu
       Machine White
              Tells the chess engine to play White.

       Machine Black
              Tells the chess engine to play Black.

       Two Machines
              Plays a game between two chess engines.

       Analysis Mode
              XBoard tells the chess engine to  start  analyzing  the  current
              game/position  and  shows  you  the  analysis as you move pieces
              around.  Note: Some chess engines do not support Analysis  mode.

              To set up a position to analyze, you do the following:

              1. Select Edit Position from the Mode Menu

              2.  Set  up  the  position.  Use the middle and right buttons to
              bring up the white and black piece menus.

              3. When you are finished, click on either  the  Black  or  White
              clock to tell XBoard which side moves first.

              4.  Select  Analysis  Mode  from  the  Mode  Menu  to  start the
              analysis.

              The analysis function can also be used when observing  games  on
              an  ICS with an engine loaded (zippy mode); the engine then will
              analyse the positions as they occur in the observed game.

       Analyze File
              This option lets you load  a  game  from  a  file  (PGN,  XBoard
              format, etc.)  and analyze it. When you select this menu item, a
              pop-up window appears and asks for a file name to load.  If  the
              file  contains  multiple games, another pop up appears that lets
              you select which game you wish to  analyze.   After  a  game  is
              loaded,  use the XBoard arrow buttons to step forwards/backwards
              through the game and  watch  the  analysis.   Note:  Some  chess
              engines do not support Analysis mode.

       ICS Client
              This  is  the  normal  mode  when XBoard is connected to a chess
              server.  If you have moved into Edit Game or Edit Position mode,
              you can select this option to get out.

              To  use  xboard  in  ICS mode, run it in the foreground with the
              -ics option, and use the terminal you started it  from  to  type
              commands  and receive text responses from the chess server.  See
              Chess Servers below for more information.

              XBoard activates some  special  position/game  editing  features
              when  you  use the ‘examine’ or ‘bsetup’ commands on ICS and you
              have ‘ICS Client’ selected on the Mode  menu.   First,  you  can
              issue  the  ICS  position-editing commands with the mouse.  Move
              pieces by dragging with mouse button 1.  To drop a new piece  on
              a  square,  press  mouse  button  2  or 3 over the square.  This
              brings up a menu of white pieces  (button  2)  or  black  pieces
              (button 3).  Additional menu choices let you empty the square or
              clear the board.  Click on the White or Black clock to  set  the
              side to play.  You cannot set the side to play or drag pieces to
              arbitrary squares while examining on ICC, but you can do  so  in
              ‘bsetup’   mode   on  FICS.   In  addition,  the  menu  commands
              ‘Forward’,  ‘Backward’,  ‘Pause’,  and  ‘Stop  Examining’   have
              special functions in this mode; see below.

       Edit Game
              Allows you to make moves for both Black and White, and to change
              moves after backing up with the ‘Backward’ command.  The  clocks
              do not run.

              In  chess engine mode, the chess engine continues to check moves
              for legality but does not participate in the game. You can bring
              the  chess  engine  into  the game by selecting ‘Machine White’,
              ‘Machine Black’, or ‘Two Machines’.

              In ICS mode, the moves are not sent  to  the  ICS:  ‘Edit  Game’
              takes  XBoard  out  of  ICS  Client mode and lets you edit games
              locally.  If you want to edit games on ICS in a way  that  other
              ICS users can see, use the ICS ‘examine’ command or start an ICS
              match against yourself.

       Edit Position
              Lets you set up an arbitrary board position.  Use mouse button 1
              to  drag pieces to new squares, or to delete a piece by dragging
              it off the board or dragging an empty square on top of  it.   To
              drop a new piece on a square, press mouse button 2 or 3 over the
              square. This brings up a menu of  white  pieces  (button  2)  or
              black  pieces  (button 3). Additional menu choices let you empty
              the square or clear the board. You can set the side to play next
              by clicking on the word White or Black at the top of the screen.
              Selecting  ‘Edit  Position’  causes  XBoard   to   discard   all
              remembered moves in the current game.

              In ICS mode, changes made to the position by ‘Edit Position’ are
              not sent to the ICS: ‘Edit Position’ takes XBoard  out  of  ‘ICS
              Client’ mode and lets you edit positions locally. If you want to
              edit positions on ICS in a way that other ICS users can see, use
              the  ICS  ‘examine’  command,  or  start  an  ICS  match against
              yourself.  (See also the ICS Client topic above.)

       Training
              Training mode lets you interactively guess the moves of  a  game
              for  one  of the players. You guess the next move of the game by
              playing the move on the board. If the move  played  matches  the
              next  move  of the game, the move is accepted and the opponent’s
              response is auto-played.  If the move played  is  incorrect,  an
              error message is displayed.  You can select this mode only while
              loading a game (that is, after selecting ‘Load  Game’  from  the
              File  menu).  While XBoard is in ‘Training’ mode, the navigation
              buttons are disabled.

       Show Game List
              Shows or hides the list of games generated  by  the  last  ‘Load
              Game’ command.

       Show Move History
              Shows  or  hides a list of moves of the current game.  This list
              allows you to move the display to any earlier  position  in  the
              game by clicking on the corresponding move.

       Show Engine Output
              Shows  or  hides  a  window  in which the thinking output of any
              loaded engines is displayed.

       Edit Tags
              Lets you edit the PGN (portable  game  notation)  tags  for  the
              current  game. After editing, the tags must still conform to the
              PGN tag syntax:

                  <tag-section> ::= <tag-pair> <tag-section>
                                          <empty>
                  <tag-pair> ::= [ <tag-name> <tag-value> ]
                  <tag-name> ::= <identifier>
                  <tag-value> ::= <string>

              See the PGN Standard for full details. Here is an example:

                  [Event "Portoroz Interzonal"]
                  [Site "Portoroz, Yugoslavia"]
                  [Date "1958.08.16"]
                  [Round "8"]
                  [White "Robert J. Fischer"]
                  [Black "Bent Larsen"]
                  [Result "1-0"]

              Any characters that  do  not  match  this  syntax  are  silently
              ignored.  Note  that the PGN standard requires all games to have
              at least the seven tags shown above. Any that you omit  will  be
              filled   in   by   XBoard  with  ‘?’  (unknown  value),  or  ‘-’
              (inapplicable value).

       Edit Comment
              Adds or modifies a comment on the current position. Comments are
              saved   by  ‘Save  Game’  and  are  displayed  by  ‘Load  Game’,
              ‘Forward’, and ‘Backward’.

       ICS Input Box
              If this option is set in  ICS  mode,  XBoard  creates  an  extra
              window  that  you can use for typing in ICS commands.  The input
              box is especially useful if you want to type in  something  long
              or  do  some  editing  on  your  input,  because output from ICS
              doesn’t get mixed in with your typing as it would  in  the  main
              terminal window.

       Pause  Pauses  updates  to  the board, and if you are playing against a
              chess engine,  also  pauses  your  clock.  To  continue,  select
              ‘Pause’  again, and the display will automatically update to the
              latest position.  The  ‘P’  button  and  keyboard  ‘p’  key  are
              equivalents.

              If  you select Pause when you are playing against a chess engine
              and it is not your move, the chess engine’s clock will  continue
              to  run  and it will eventually make a move, at which point both
              clocks will stop. Since board updates are paused,  however,  you
              will  not see the move until you exit from Pause mode (or select
              Forward).  This behavior is meant to simulate adjournment with a
              sealed move.

              If  you select Pause while you are observing or examining a game
              on a chess server, you can step  backward  and  forward  in  the
              current history of the examined game without affecting the other
              observers and examiners, and without having  your  display  jump
              forward  to the latest position each time a move is made. Select
              Pause again to reconnect yourself to the current  state  of  the
              game on ICS.

              If  you  select  ‘Pause’  while you are loading a game, the game
              stops loading. You can load more  moves  manually  by  selecting
              ‘Forward’,  or  resume  automatic  loading  by selecting ‘Pause’
              again.

   Action Menu
       Accept Accepts a pending match offer. If there is more than  one  offer
              pending,  you  will  have  to  type  in  a more specific command
              instead of using this menu choice.

       Decline
              Declines a pending offer (match, draw, adjourn, etc.). If  there
              is  more than one offer pending, you will have to type in a more
              specific command instead of using this menu choice.

       Call Flag
              Calls your opponent’s flag, claiming a win on time, or  claiming
              a  draw  if  you  are  both  out of time. You can also call your
              opponent’s flag by clicking on his  clock  or  by  pressing  the
              keyboard ‘t’ key.

       Draw   Offers  a  draw  to  your opponent, accepts a pending draw offer
              from your opponent, or  claims  a  draw  by  repetition  or  the
              50-move  rule,  as  appropriate.  The  ‘d’  key  is  a  keyboard
              equivalent.

       Adjourn
              Asks your opponent to agree to adjourning the current  game,  or
              agrees to a pending adjournment offer from your opponent.

       Abort  Asks  your  opponent  to  agree to aborting the current game, or
              agrees to a pending abort offer from your opponent.  An  aborted
              game  ends immediately without affecting either player’s rating.

       Resign Resigns the game to your opponent. The  shifted  ‘R’  key  is  a
              keyboard equivalent.

       Stop Observing
              Ends  your participation in observing a game, by issuing the ICS
              observe command with no arguments. ICS mode only.

       Stop Examining
              Ends your participation in examining a game, by issuing the  ICS
              unexamine command. ICS mode only.

       Adjudicate to White
       Adjudicate to Black
       Adjudicate Draw
              Terminate  an ongoing game in Two-Machines mode (including match
              mode), with as result a win for white, for  black,  or  a  draw,
              respectively.   The  PGN  file  of  the  game will accompany the
              result string by the comment "user adjudication".

   Step Menu
       Backward
              Steps backward through a series of remembered moves.  The  ‘[<]’
              button  and the ‘b’ key are equivalents, as is turning the mouse
              wheel towards you.  In addition, pressing the Control key  steps
              back one move, and releasing it steps forward again.

              In  most  modes,  ‘Backward’  only  lets  you  look  back at old
              positions; it does not retract moves. This is the  case  if  you
              are  playing against a chess engine, playing or observing a game
              on an ICS, or loading a game.  If you select ‘Backward’  in  any
              of these situations, you will not be allowed to make a different
              move. Use ‘Retract Move’ or ‘Edit Game’ if you  want  to  change
              past moves.

              If  you  are  examining  an ICS game, the behavior of ‘Backward’
              depends on whether XBoard is in Pause mode.  If  Pause  mode  is
              off,  ‘Backward’ issues the ICS backward command, which backs up
              everyone’s view of the game and allows you to make  a  different
              move.  If  Pause mode is on, ‘Backward’ only backs up your local
              view.

       Forward
              Steps forward through a series of remembered moves (undoing  the
              effect  of ‘Backward’) or forward through a game file. The ‘[>]’
              button and the ‘f’ key are equivalents, as is turning the  mouse
              wheel away from you.

              If  you  are  examining  an  ICS  game,  the behavior of Forward
              depends on whether XBoard is in Pause mode.  If  Pause  mode  is
              off,  ‘Forward’  issues  the  ICS  forward  command, which moves
              everyone’s view of the game forward along the current  line.  If
              Pause  mode is on, ‘Forward’ only moves your local view forward,
              and it will not go past the position that the game was  in  when
              you paused.

       Back to Start
              Jumps  backward  to  the  first remembered position in the game.
              The ‘[<<]’ button and the shifted ‘B’ key are equivalents.

              In most modes, Back to Start only lets  you  look  back  at  old
              positions;  it  does  not retract moves. This is the case if you
              are playing against a local chess engine, playing or observing a
              game  on  a chess server, or loading a game. If you select ‘Back
              to Start’ in any of these situations, you will not be allowed to
              make  different  moves. Use ‘Retract Move’ or ‘Edit Game’ if you
              want to change past moves; or use Reset to start a new game.

              If you are examining an ICS game, the behavior of @samp{Back  to
              Start} depends on whether XBoard is in Pause mode. If Pause mode
              is off,  ‘Back  to  Start’  issues  the  ICS  ‘backward  999999’
              command, which backs up everyone’s view of the game to the start
              and allows you to make different moves. If  Pause  mode  is  on,
              @samp{Back to Start} only backs up your local view.

       Forward to End
              Jumps  forward  to the last remembered position in the game. The
              ‘[>>]’ button and the shifted ‘F’ key are equivalents.

              If you are examining an ICS game, the behavior of  @samp{Forward
              to  End}  depends  on  whether XBoard is in Pause mode. If Pause
              mode is off, ‘Forward to End’ issues the  ICS  ‘forward  999999’
              command,  which moves everyone’s view of the game forward to the
              end of the current line. If Pause mode is on, ‘Forward  to  End’
              only  moves your local view forward, and it will not go past the
              position that the game was in when you paused.

       Revert If you are examining an ICS game and Pause mode is  off,  issues
              the ICS command ‘revert’.

       Truncate Game
              Discards  all  remembered  moves  of the game beyond the current
              position. Puts XBoard into ‘Edit Game’ mode if it was not  there
              already.

       Move Now
              Forces  the  chess engine to move immediately. Chess engine mode
              only.

       Retract Move
              Retracts your last move. In chess engine mode, you can  do  this
              only  after  the  chess  engine has replied to your move; if the
              chess engine is still thinking, use ‘Move  Now’  first.  In  ICS
              mode,   ‘Retract  Move’  issues  the  command  ‘takeback  1’  or
              ‘takeback 2’ depending on whether it is your opponent’s move  or
              yours.

   Options Menu
       Flip View
              Inverts  your  view  of  the chess board for the duration of the
              current game. Starting a new game returns the board  to  normal.
              The ‘v’ key is a keyboard equivalent.

       Adjudications
              Pops  up  a  sub-menu  where  you  can enable or disable various
              adjudications that XBoard can perform  in  engine-engine  games.
              You  can  instruct  XBoard  to  detect and terminate the game on
              checkmate or stalemate, even if the engines would not do so,  to
              verify  engine result claims (forfeiting engines that make false
              claims), rather than naively following the  engine,  to  declare
              draw  on  positions  which  can  never be won for lack of mating
              material, (e.g. KBK), or which are impossible to win unless  the
              opponent   seeks   its   own  demise  (e.g.  KBKN).   For  these
              adjudications to work, ‘Test Legality’ should  be  switched  on.
              It  is  also possible to instruct XBoard to enforce a 50-move or
              3-fold-repeat rule and automatically declare draw (after a user-
              adjustable  number  of moves or repeats) even if the engines are
              prepared to go on.  It is also possible to have  XBoard  declare
              draw on games that seem to drag on forever, or adjudicate a loss
              if both engines agree (for 3 consecutive moves) that one of them
              is  behind more than a user-adjustable score threshold.  For the
              latter adjudication to work, XBoard should be able  to  properly
              understand  the  engine’s  scores. To facilitate the latter, you
              can inform xboard here if the engines  report  scores  from  the
              viewpoint of white, or from that of their own color.

       Engine Settings
              Pops  up  a  sub-menu  where  you can set some engine parameters
              common to most engines, such as hash-table size, tablebase cache
              size, maximum number of processors that SMP engines can use, and
              where to find the Polyglot adapter needed  to  run  UCI  engines
              under   XBoard.   The  feature  that  allows  setting  of  these
              parameters on engines is new since XBoard 4.3.15,  so  not  many
              XBoard/WinBoard  engines  respond  to  it  yet,  but UCI engines
              should.  It is also possible to specify a GUI opening book here,
              i.e.  an  opening  book  that XBoard consults for any position a
              playing engine gets in.  It then forces the engine to  play  the
              book  move, rather than to think up its own, if that position is
              found  in  the  book.   The  book  can  switched  on   and   off
              independently for either engine.

       Time Control
              Pops up a sub-menu where you can set the time-control parameters
              interactively.  Allows you to select  classical  or  incremental
              time  controls, set the moves per session, session duration, and
              time increment.  Also allows specification of time-odds  factors
              for  one  or  both  engines.   If an engine is given a time-odds
              factor N, all time quota it gets, be it at the  beginning  of  a
              session  or  through  the time increment or fixed time per move,
              will be divided by N.

       Always Queen
              If this option is off, XBoard brings up a  dialog  box  whenever
              you  move a pawn to the last rank, asking what piece you want to
              promote it to. If the option is  true,  your  pawns  are  always
              promoted to queens. Your opponent can still under-promote.

       Animate Dragging
              If  Animate  Dragging is on, while you are dragging a piece with
              the mouse, an image of the piece follows the mouse  cursor.   If
              Animate  Dragging  is off, there is no visual feedback while you
              are dragging a piece, but if Animate Moving is on, the move will
              be animated when it is complete.

       Animate Moving
              If Animate Moving is on, all piece moves are animated.  An image
              of the piece is shown moving from the  old  square  to  the  new
              square  when  the move is completed (unless the move was already
              animated by Animate Dragging).  If  Animate  Moving  is  off,  a
              moved  piece  instantly  disappears  from  its  old  square  and
              reappears on its new square when the move is complete.

       Auto Comment
              If this option is on, any remarks made  on  ICS  while  you  are
              observing  or  playing  a  game are recorded as a comment on the
              current move.  This includes remarks made with the ICS  commands
              ‘say’,  ‘tell’,  ‘whisper’,  and  ‘kibitz’.  Limitation: remarks
              that you type yourself are not recognized; XBoard scans only the
              output from ICS, not the input you type to it.

       Auto Flag
              If  this option is on and one player runs out of time before the
              other, XBoard will automatically call his flag, claiming  a  win
              on  time.  In ICS mode, Auto Flag will only call your opponent’s
              flag, not yours, and the ICS may award you a draw instead  of  a
              win  if  you  have insufficient mating material.  In local chess
              engine mode, XBoard may call either player’s flag and  will  not
              take material into account.

       Auto Flip View
              If  the  Auto  Flip View option is on when you start a game, the
              board will be automatically oriented so  that  your  pawns  move
              from the bottom of the window towards the top.

       Auto Observe
              If this option is on and you add a player to your ‘gnotify’ list
              on ICS, XBoard will automatically observe all of  that  player’s
              games, unless you are doing something else (such as observing or
              playing a game of your own) when  one  starts.   The  games  are
              displayed  from  the point of view of the player on your gnotify
              list; that is, his pawns move from  the  bottom  of  the  window
              towards  the top.  Exceptions:  If both players in a game are on
              your gnotify list, if your ICS ‘highlight’ variable is set to 0,
              or  if the ICS you are using does not properly support observing
              from Black’s point of view, you will see the game  from  White’s
              point of view.

       Auto Raise Board
              If this option is on, whenever a new game begins, the chessboard
              window is deiconized (if necessary) and raised to the top of the
              stack of windows.

       Auto Save
              If  this option is true, at the end of every game XBoard prompts
              you for a file name and appends a record of the game to the file
              you specify.  Disabled if the ‘saveGameFile’ command-line option
              is set, as in that case all games are  saved  to  the  specified
              file.  See Load and Save options.

       Blindfold
              If  this  option  is  on, XBoard displays the board as usual but
              does not display pieces or move highlights.  You can still  move
              in  the  usual  way  (with  the  mouse or by typing moves in ICS
              mode), even though the pieces are invisible.

       Flash Moves
              If this option is on, whenever a move is  completed,  the  moved
              piece  flashes.   The  number  of  times  to flash is set by the
              flashCount command-line option; it defaults to 3 if Flash  Moves
              is first turned on from the menu.

              If  you  are  playing  a  game  on  an  ICS, the board is always
              oriented at the start of the game so that your pawns  move  from
              the  bottom  of  the  window  towards  the  top.  Otherwise, the
              starting orientation is determined  by  the  ‘flipView’  command
              line  option;  if  it is false (the default), White’s pawns move
              from bottom to top at the start of each game;  if  it  is  true,
              Black’s  pawns  move  from  bottom  to  top.  See User interface
              options.

       Get Move List
              If this option is on, whenever XBoard receives the  first  board
              of  a  new  ICS  game  (or  a  different game from the one it is
              currently displaying), it retrieves the list of past moves  from
              the  ICS.   You can then review the moves with the ‘Forward’ and
              ‘Backward’ commands or save them with ‘Save  Game’.   You  might
              want  to turn off this option if you are observing several blitz
              games at once, to keep from wasting time and  network  bandwidth
              fetching  the  move  lists  over  and  over.  When you turn this
              option on from the menu, XBoard  immediately  fetches  the  move
              list of the current game (if any).

       Highlight Last Move
              If Highlight Last Move is on, after a move is made, the starting
              and ending squares remain highlighted. In  addition,  after  you
              use  Backward  or Back to Start, the starting and ending squares
              of the last move to be unmade are highlighted.

       Move Sound
              If this option is on, XBoard alerts you by playing a sound after
              each  of  your  opponent’s moves (or after every move if you are
              observing a game on the Internet Chess Server).   The  sound  is
              not  played after moves you make or moves read from a saved game
              file. By default, the sound is the terminal bell,  but  on  some
              systems  you  can  change it to a sound file using the soundMove
              option; see below.

              If you turn on this option when using XBoard with  the  Internet
              Chess  Server,  you  will probably want to give the ‘set bell 0’
              command to the ICS,  since  otherwise  the  ICS  will  ring  the
              terminal  bell  after every move (not just yours). (The ‘.icsrc’
              file is a good place for this; see ICS options.)

       ICS Alarm
              When this option is on, an alarm sound is played when your clock
              counts  down  to  the icsAlarmTime (by default, 5 seconds) in an
              ICS  game.   For  games  with  time  controls  that  include  an
              increment,  the alarm will sound each time the clock counts down
              to the  icsAlarmTime.   By  default,  the  alarm  sound  is  the
              terminal  bell, but on some systems you can change it to a sound
              file using the soundIcsAlarm option; see below.

       Old Save Style
              If this option is off, XBoard saves games in PGN (portable  game
              notation)  and positions in FEN (Forsythe-Edwards notation).  If
              the option is on, a save style that  is  compatible  with  older
              versions  of  XBoard is used instead.  The old position style is
              more  human-readable  than  FEN;  the  old  game  style  has  no
              particular advantages.

       Periodic Updates
              If  this  option is off (or if you are using a chess engine that
              does not support periodic updates),  the  analysis  window  will
              only be updated when the analysis changes. If this option is on,
              the Analysis Window will be updated every two seconds.

       Ponder Next Move
              If this option is off, the chess engine will think only when  it
              is  on  move.   If  the option is on, the engine will also think
              while waiting for you to make your move.

       Popup Exit Message
              If this option is on, when XBoard wants  to  display  a  message
              just  before  exiting, it brings up a modal dialog box and waits
              for you to click OK before  exiting.   If  the  option  is  off,
              XBoard  prints  the message to standard error (the terminal) and
              exits immediately.

       Popup Move Errors
              If this option is off, when you make an error in moving (such as
              attempting an illegal move or moving the wrong color piece), the
              error message is displayed in the message area.  If  the  option
              is  on,  move  errors are displayed in small pop-up windows like
              other errors.   You  can  dismiss  an  error  pop-up  either  by
              clicking  its  OK  button  or by clicking anywhere on the board,
              including down-clicking to start a move.

       Premove
              If this option is on while playing a game on  an  ICS,  you  can
              register  your  next  planned move before it is your turn.  Move
              the piece with the mouse in the ordinary way, and  the  starting
              and ending squares will be highlighted with a special color (red
              by default).  When it is your turn, if your registered  move  is
              legal,  XBoard  will send it to ICS immediately; if not, it will
              be ignored and you can make a different  move.   If  you  change
              your  mind  about your premove, either make a different move, or
              double-click on any piece to cancel the move entirely.

       Quiet Play
              If this option is on, XBoard will  automatically  issue  an  ICS
              ‘set shout 0’ command whenever you start a game and a ‘set shout
              1’ command whenever you finish  one.   Thus,  you  will  not  be
              distracted by shouts from other ICS users while playing.

       Show Coords
              If  this  option  is  on,  XBoard displays algebraic coordinates
              along the board’s left and bottom edges.

       Hide Thinking
              If this option is off, the chess engine’s notion  of  the  score
              and  best line of play from the current position is displayed as
              it is thinking. The score indicates how many pawns ahead (or  if
              negative,  behind)  the  chess  engine  thinks it is. In matches
              between two machines, the score is prefixed by  ‘W’  or  ‘B’  to
              indicate  whether it is showing White’s thinking or Black’s, and
              only the thinking of the engine that is on move is shown.

       Test Legality
              If this option is on, XBoard tests whether the moves you try  to
              make  with  the  mouse  are legal and refuses to let you make an
              illegal move.  Moves loaded from a file  with  ‘Load  Game’  are
              also checked.  If the option is off, all moves are accepted, but
              if a local chess engine or the ICS is active,  they  will  still
              reject  illegal moves.  Turning off this option is useful if you
              are playing a chess variant with  rules  that  XBoard  does  not
              understand.   (Bughouse,  suicide,  and  wild variants where the
              king may castle after starting  on  the  d  file  are  generally
              supported with Test Legality on.)

   Help Menu
       Info XBoard
              Displays  the  XBoard  documentation  in  info format.  For this
              feature to work, you must have the GNU info program installed on
              your  system,  and the file ‘xboard.info’ must either be present
              in the current working directory, or have been installed by  the
              ‘make install’ command when you built XBoard.

       Man XBoard
              Displays  the XBoard documentation in man page format.  For this
              feature to work, the file ‘xboard.6’ must have been installed by
              the  ‘make  install’  command  when  you  built  XBoard, and the
              directory it was placed in must be on the search path  for  your
              system’s ‘man’ command.

       Hint   Displays a move hint from the chess engine.

       Book   Displays  a  list  of  possible  moves  from  the chess engine’s
              opening book.  The exact format depends on what chess engine you
              are  using.  With GNU Chess 4, the first column gives moves, the
              second column gives one possible response for each move, and the
              third  column shows the number of lines in the book that include
              the move from the first column. If you select  this  option  and
              nothing happens, the chess engine is out of its book or does not
              support this feature.

       About XBoard
              Shows the current XBoard version number.

   Other Shortcut Keys
       Iconize
              Pressing the ‘i’ or ‘c’ key iconizes XBoard. The graphical  icon
              displays a white knight if it is White’s move, or a black knight
              if it is Black’s move. If your X window  manager  displays  only
              text  icons,  not graphical ones, check its documentation; there
              is probably a way to enable graphical icons.  If you  get  black
              and white reversed, we would like to hear about it; see Problems
              below for instructions on how to report this problem.

       You  can  add  or  remove  shortcut  keys   using   the   X   resources
       ‘form.translations’.  Here  is  an  example  of  what  would go in your
       ‘.Xresources’ file:

           XBoard*form.translations: \
             Shift<Key>?: AboutGameProc() \n\
             <Key>y: AcceptProc() \n\
             <Key>n: DeclineProc() \n\
             <Key>i: NothingProc()

       Binding a key to ‘NothingProc’ makes it do nothing, thus removing it as
       a shortcut key. The XBoard commands that can be bound to keys are:

           AbortProc, AboutGameProc, AboutProc, AcceptProc, AdjournProc,
           AlwaysQueenProc, AnalysisModeProc, AnalyzeFileProc,
           AnimateDraggingProc, AnimateMovingProc, AutobsProc, AutoflagProc,
           AutoflipProc, AutoraiseProc, AutosaveProc, BackwardProc,
           BlindfoldProc, BookProc, CallFlagProc, CopyGameProc, CopyPositionProc,
           DebugProc, DeclineProc, DrawProc, EditCommentProc, EditGameProc,
           EditPositionProc, EditTagsProc, EnterKeyProc, FlashMovesProc,
           FlipViewProc, ForwardProc, GetMoveListProc, HighlightLastMoveProc,
           HintProc, Iconify, IcsAlarmProc, IcsClientProc, IcsInputBoxProc,
           InfoProc, LoadGameProc, LoadNextGameProc, LoadNextPositionProc,
           LoadPositionProc, LoadPrevGameProc, LoadPrevPositionProc,
           LoadSelectedProc, MachineBlackProc, MachineWhiteProc, MailMoveProc,
           ManProc, MoveNowProc, MoveSoundProc, NothingProc, OldSaveStyleProc,
           PasteGameProc, PastePositionProc, PauseProc, PeriodicUpdatesProc,
           PonderNextMoveProc, PopupExitMessageProc, PopupMoveErrorsProc,
           PremoveProc, QuietPlayProc, QuitProc, ReloadCmailMsgProc,
           ReloadGameProc, ReloadPositionProc, RematchProc, ResetProc,
           ResignProc, RetractMoveProc, RevertProc, SaveGameProc,
           SavePositionProc, ShowCoordsProc, ShowGameListProc, ShowThinkingProc,
           StopExaminingProc, StopObservingProc, TestLegalityProc, ToEndProc,
           ToStartProc, TrainingProc, TruncateGameProc, and TwoMachinesProc.

OPTIONS

       This section documents the command-line options to XBoard.  You can set
       these options in two ways: by typing them on the shell command line you
       use  to  start  XBoard, or by setting them as X resources (typically in
       your ‘.Xresources’ file).  Many of the options cannot be changed  while
       XBoard  is  running;  others set the initial state of items that can be
       changed with the Options menu.

       Most of the options have both a long name and a short name. To  turn  a
       boolean  option  on  or off from the command line, either give its long
       name followed by the value true or false (‘-longOptionName  true’),  or
       give  just  the short name to turn the option on (‘-opt’), or the short
       name preceded by ‘x’ to turn the option off (‘-xopt’). For options that
       take strings or numbers as values, you can use the long or short option
       names interchangeably.

       Each option corresponds to an X resource with the same name, so if  you
       like, you can set options in your ‘.Xresources’ file or in a file named
       ‘XBoard’ in your home directory.  For options that have two names,  the
       longer  one is the name of the corresponding X resource; the short name
       is not recognized.  To turn  a  boolean  option  on  or  off  as  an  X
       resource,  give  its  long  name  followed  by  the value true or false
       (‘XBoard*longOptionName: true’).

   Chess Engine Options
       -tc or -timeControl minutes[:seconds]
              Each player begins with  his  clock  set  to  the  ‘timeControl’
              period.    Default:   5   minutes.    The   additional   options
              ‘movesPerSession’ and ‘timeIncrement’ are mutually exclusive.

       -mps or -movesPerSession moves
              When both players  have  made  ‘movesPerSession’  moves,  a  new
              ‘timeControl’  period  is  added  to  both  clocks.  Default: 40
              moves.

       -inc or -timeIncrement seconds
              If this  option  is  specified,  ‘movesPerSession’  is  ignored.
              Instead,  after  each player’s move, ‘timeIncrement’ seconds are
              added to his clock.  Use ‘-inc 0’ if you  want  to  require  the
              entire  game  to  be played in one ‘timeControl’ period, with no
              increment.  Default: -1, which specifies ‘movesPerSession’ mode.

       -clock/-xclock or -clockMode true/false
              Determines  whether  or  not  to  display  the  chess clocks. If
              clockMode is false, the clocks are not shown, but the side  that
              is  to play next is still highlighted. Also, unless ‘searchTime’
              is set, the chess engine still keeps track of the clock time and
              uses it to determine how fast to make its moves.

       -st or -searchTime minutes[:seconds]
              Tells the chess engine to spend at most the given amount of time
              searching for each of its moves. Without this option, the  chess
              engine  chooses its search time based on the number of moves and
              amount of time remaining until the next time  control.   Setting
              this option also sets clockMode to false.

       -depth or -searchDepth number
              Tells the chess engine to look ahead at most the given number of
              moves when searching for a move to make.  Without  this  option,
              the chess engine chooses its search depth based on the number of
              moves and amount of time remaining until the next time  control.
              With  the option, the engine will cut off its search early if it
              reaches the specified depth.

       -firstNPS number
       -secondNPS number
              Tells the chess engine to use an internal time standard based on
              its  node count, rather then wall-clock time, to make its timing
              decisions.  The time in virtual seconds should  be  obtained  by
              dividing  the  node  count  through  the  given number, like the
              number was a rate in nodes per second.  Xboard will  manage  the
              clocks  in  accordance with this, relying on the number of nodes
              reported by the engine in its  thinking  output.  If  the  given
              number  equals  zero,  it  can  obviously not be used to convert
              nodes to seconds, and the time reported by the engine is used to
              decrement  the  XBoard clock in stead. The engine is supposed to
              report in CPU time it uses, rather than wall-clock time, in this
              mode.  This  option  can  provide  fairer conditions for engine-
              engine matches on heavily loaded machines,  or  with  very  fast
              games  (where the wall clock is too inaccurate).  ‘showThinking’
              must be on for this option to work. Default: -1 (off).  Not many
              engines might support this yet!

       -firstTimeOdds factor
       -secondTimeOdds factor
              Reduces  the  time  given  to  the mentioned engine by the given
              factor.  If pondering is off, the  effect  is  indistinguishable
              from  what  would happen if the engine was running on an n-times
              slower machine. Default: 1.

       -timeOddsMode mode
              This option determines  how  the  case  is  handled  where  both
              engines  have  a time-odds handicap.  If mode=1, the engine that
              gets the  most  time  will  always  get  the  nominal  time,  as
              specified  by  the time-control options, and its opponent’s time
              is renormalized accordingly.  If mode=0, both play with  reduced
              time. Default: 0.

       -hideThinkingFromHuman true/false
              Controls  the  Hide  Thinking option. See Options Menu. Default:
              true.   (Replaces  the  Show-Thinking  option  of  older  xboard
              versions.)

       -thinking/-xthinking or -showThinking true/false
              Forces the engine to send thinking output to xboard.  Used to be
              the only way to control if  thinking  output  was  displayed  in
              older  xboard versions, but as the thinking output in xboard 4.3
              is also used for several other purposes  (adjudication,  storing
              in  PGN  file)  the  display  of it is now controlled by the new
              option Hide Thinking. See Options Menu. Default: false.  (But if
              xboard  needs the thinking output for some purpose, it makes the
              engine send it despite the setting of this option.)

       -ponder/-xponder or -ponderNextMove true/false
              Sets the  Ponder  Next  Move  menu  option.  See  Options  Menu.
              Default: true.

       -smpCores number
              Specifies the maximum number of CPUs an SMP engine is allowed to
              use.  Only works for engines that support  the  XBoard/WinBoard-
              protocol cores feature.

       -mg or -matchGames n
              Automatically  runs  an  n-game match between two chess engines,
              with   alternating   colors.    If   the    ‘loadGameFile’    or
              ‘loadPositionFile’  option  is set, XBoard starts each game with
              the given opening moves or the given  position;  otherwise,  the
              games  start  with  the standard initial chess position.  If the
              ‘saveGameFile’ option is set, a move record  for  the  match  is
              appended to the specified file. If the ‘savePositionFile’ option
              is set, the final position reached in each game of the match  is
              appended  to  the specified file. When the match is over, XBoard
              displays the match score and exits. Default: 0  (do  not  run  a
              match).

       -mm/-xmm or -matchMode true/false
              Setting   ‘matchMode’   to   true   is   equivalent  to  setting
              ‘matchGames’ to 1.

       -sameColorGames n
              Automatically runs an n-game match between  two  chess  engines,
              without  alternating  colors.  Otherwise the same applies as for
              the ‘-matchGames’ option, over which it takes precedence if both
              are specified. (See there.)  Default: 0 (do not run a match).

       -fcp or -firstChessProgram program
              Name of first chess engine.  Default: ‘Fairy-Max’.

       -scp or -secondChessProgram program
              Name  of  second chess engine, if needed.  A second chess engine
              is started only in Two Machines (match) mode.  Default:  ‘Fairy-
              Max’.

       -fb/-xfb or -firstPlaysBlack true/false
              In  games  between two chess engines, firstChessProgram normally
              plays white.  If this option is  true,  firstChessProgram  plays
              black.   In  a  multi-game match, this option affects the colors
              only for the first game;  they  still  alternate  in  subsequent
              games.

       -fh or -firstHost host
       -sh or -secondHost host
              Hosts  on  which  the  chess engines are to run. The default for
              each is ‘localhost’. If you specify another  host,  XBoard  uses
              ‘rsh’  to  run  the  chess  engine  there. (You can substitute a
              different remote shell program for rsh using  the  ‘remoteShell’
              option described below.)

       -fd or -firstDirectory dir
       -sd or -secondDirectory dir
              Working  directories  in  which the chess engines are to be run.
              The default is "", which means to run the chess  engine  in  the
              same  working  directory  as  XBoard  itself.  (See the CHESSDIR
              environment variable.)  This option is effective only  when  the
              chess engine is being run on the local host; it does not work if
              the engine is run remotely using the -fh or -sh option.

       -initString string
       -secondInitString string
              The string that is sent to initialize each chess  engine  for  a
              new game.  Default:

                  new
                  random

              Setting this option from the command line is tricky, because you
              must type in real newline characters, including one at the  very
              end.  In most shells you can do this by entering a ‘\’ character
              followed by a newline. It is easier to set the option from  your
              ‘.Xresources’  file;  in that case you can include the character
              sequence ‘\n’ in the string, and  it  will  be  converted  to  a
              newline.

              If you change this option, don’t remove the ‘new’ command; it is
              required by all chess engines to start a new game.

              You can remove the ‘random’ command if you  like;  including  it
              causes  GNU  Chess 4 to randomize its move selection slightly so
              that it doesn’t play the same moves in every game.  Even without
              ‘random’,  GNU  Chess  4 randomizes its choice of moves from its
              opening book.  Many other  chess  engines  ignore  this  command
              entirely and always (or never) randomize.

              You  can  also  try adding other commands to the initString; see
              the documentation of the chess engine you are using for details.

       -firstComputerString string
       -secondComputerString string
              The  string  that is sent to the chess engine if its opponent is
              another computer chess engine.   The  default  is  ‘computer\n’.
              Probably  the  only useful alternative is the empty string (‘’),
              which keeps the engine from knowing that it is  playing  another
              computer.

       -reuse/-xreuse or -reuseFirst true/false
       -reuse2/-xreuse2 or -reuseSecond true/false
              If  the option is false, XBoard kills off the chess engine after
              every game and starts it again for the next game.  If the option
              is  true (the default), XBoard starts the chess engine only once
              and uses it repeatedly to play multiple games.  Some  old  chess
              engines  may  not  work  properly  when  reuse is turned on, but
              otherwise games will start faster if it is left on.

       -firstProtocolVersion version-number
       -secondProtocolVersion version-number
              This  option  specifies  which  version  of  the  chess   engine
              communication protocol to use.  By default, version-number is 2.
              In version 1, the "protover" command is not sent to the  engine;
              since  version 1 is a subset of version 2, nothing else changes.
              Other values for version-number are not supported.

       -firstScoreAbs true/false
       -secondScoreAbs true/false
              If this option is set, the score reported by the engine is taken
              to  be that in favor of white, even when the engine plays black.
              Important when XBoard uses the score for  adjudications,  or  in
              PGN reporting.

       -niceEngines priority
              This  option  allows  you  to  lower  the priority of the engine
              processes, so that the generally insatiable hunger for CPU  time
              of  chess  engines  does  not  interfere  so  much  with  smooth
              operation of XBoard (or the  rest  of  your  system).   Negative
              values   could  increase  the  engine  priority,  which  is  not
              recommended.

       -firstOptions string
       -secondOptions string
              The  given  string  is  a  comma-separated   list   of   (option
              name=option   value)   pairs,   like   the   following  example:
              "style=Karpov,blunder rate=0".  If an option  announced  by  the
              engine   at   startup   through  the  feature  commands  of  the
              XBoard/WinBoard protocol matches one of the option  names  (i.e.
              "style"  or  "blunder rate"), it would be set to the given value
              (i.e. "Karpov" or 0) through a corresponding option  command  to
              the  engine.   This provided that the type of the value (text or
              numeric) matches as well.

       -firstNeedsNoncompliantFEN string
       -secondNeedsNoncompliantFEN string
              The castling rights and e.p. fields  of  the  FEN  sent  to  the
              mentioned  engine  with the setboard command will be replaced by
              the given string. This can for instance be used to  run  engines
              that do not understand Chess960 FENs in variant fischerandom, to
              make them at least  understand  the  opening  position,  through
              setting  the string to "KQkq -". (Note you also have to give the
              e.p. field!)  Other possible applications are to  provide  work-
              arounds for engines that want to see castling and e.p. fields in
              variants that do not have castling or e.p.  (shatranj,  courier,
              xiangqi,  shogi) so that XBoard would normally omit them (string
              = "- -"), or to add variant-specific fields  that  are  not  yet
              supported  by  XBoard  (e.g. to indicate the number of checks in
              3check).

   UCI + WB Engine Settings
       -fUCI or -firstIsUCI true/false
       -sUCI or -secondIsUCI true/false
              Indicates if the mentioned engine  executable  file  is  an  UCI
              engine,  and  should be run with the aid of the Polyglot adapter
              rather than directly.  Xboard  will  then  pass  the  other  UCI
              options  and  engine  name  to Polyglot through a .ini temporary
              file created for the purpose.

       -PolyglotDir filename
              Gives the name of the directory in which  the  Polyglot  adapter
              for     UCI     engines    expects    its    files.     Default:
              "/usr/local/share/polyglot".

       -usePolyglotBook true/false
              Specifies if the Polyglot book should be used.

       -PolyglotBook filename
              Gives the filename of the opening book that Polyglot should use.
              From  XBoard 4.3.15 on, native XBoard/WinBoard engines will also
              use   the   opening   book   specified   here,   provided    the
              ‘usePolyglotBook’   option  is  set  to  true,  and  the  option
              ‘firstHasOwnBookUCI’ or ‘secondHasOwnBookUCI’  applying  to  the
              engine  is  set to false.  The engine will be kept in force mode
              as long as the current position is  in  book,  and  XBoard  will
              select the book moves for it. Default "".

       -fNoOwnBookUCI or -firstXBook or -firstHasOwnBookUCI true/false
       -sNoOwnBookUCI or -secondXBook or -secondHasOwnBookUCI true/false
              Indicates  if  the  mentioned engine has its own opening book it
              should play from, rather than using the  external  book  through
              XBoard. Default: false.

       -defaultHashSize n
              Sets  the  size  of the hash table to n MegaBytes. Together with
              the EGTB cache size this number is also used  to  calculate  the
              memory  setting  of  XBoard/WinBoard  engines,  for  those  that
              support the memory  feature  of  the  XBoard/WinBoard  protocol.
              Default: 64.

       -defaultCacheSizeEGTB n
              Sets  the  size  of the EGTB cache to n MegaBytes. Together with
              the hash-table size this number is also used  to  calculate  the
              memory  setting  of  XBoard/WinBoard  engines,  for  those  that
              support the memory  feature  of  the  XBoard/WinBoard  protocol.
              Default: 4.

       -defaultPathEGTB filename
              Gives  the  name  of the directory where the end-game tablebases
              are     installed,     for      UCI      engines.       Default:
              "/usr/local/share/egtb".

       -egtFormats string
              Specifies  which  end-game tables are installed on the computer,
              and where.  The argument is a  comma-separated  list  of  format
              specifications,  each specification consisting of a format name,
              a    colon,    and    a    directory     path     name,     e.g.
              "nalimov:/usr/local/share/egtb".   If the name part matches that
              of a format that the engine requests through a feature  command,
              xboard  will  relay  the path name for this format to the engine
              through an  egtpath  command.   One  egtpath  command  for  each
              matching format will be sent.  Popular formats are "nalimov" DTM
              tablebases and "scorpio" bitbases.  Default: "".

   ICS options
       -ics/-xics or -internetChessServerMode true/false
              Connect with an Internet Chess Server to play chess against  its
              other  users,  observe  games  they are playing, or review games
              that have recently finished. Default: false.

       -icshost or -internetChessServerHost host
              The Internet host name or address of the chess server to connect
              to  when in ICS mode. Default: ‘chessclub.com’.  Another popular
              chess server to try is ‘freechess.org’.  If  your  site  doesn’t
              have  a  working  Internet  name server, try specifying the host
              address in numeric form.  You  may  also  need  to  specify  the
              numeric  address  when using the icshelper option with timestamp
              or timeseal (see below).

       -icsport or -internetChessServerPort port-number
              The port number to use when connecting to a chess server in  ICS
              mode. Default: 5000.

       -icshelper or -internetChessServerHelper prog-name
              An  external  helper  program used to communicate with the chess
              server.  You would set it to "timestamp" for ICC (chessclub.com)
              or  "timeseal"  for  FICS  (freechess.org),  after obtaining the
              correct version of timestamp or timeseal for your computer.  See
              "help  timestamp"  on  ICC  and  "help  timeseal" on FICS.  This
              option is shorthand for ‘-useTelnet -telnetProgram program’.

       -telnet/-xtelnet or -useTelnet true/false
              This option is poorly named; it should be called useHelper.   If
              set  to  true, it instructs XBoard to run an external program to
              communicate with the Internet Chess Server.  The program to  use
              is  given  by  the telnetProgram option.  If the option is false
              (the default), XBoard opens  a  TCP  socket  and  uses  its  own
              internal  implementation  of  the telnet protocol to communicate
              with the ICS. See Firewalls.

       -telnetProgram prog-name
              This option is poorly named; it should be called  helperProgram.
              It  gives  the  name  of  the telnet program to be used with the
              ‘gateway’ and ‘useTelnet’ options.  The default is ‘telnet’. The
              telnet    program    is    invoked    with    the    value    of
              ‘internetChessServerHost’ as its first argument and the value of
              ‘internetChessServerPort’   as   its   second   argument.    See
              Firewalls.

       -gateway host-name
              If this option is set to a host name, XBoard  communicates  with
              the   Internet   Chess   Server   by  using  ‘rsh’  to  run  the
              ‘telnetProgram’ on the given host,  instead  of  using  its  own
              internal   implementation   of  the  telnet  protocol.  You  can
              substitute a different remote shell program for ‘rsh’ using  the
              ‘remoteShell’ option described below.  See Firewalls.

       -internetChessServerCommPort or -icscomm dev-name
              If  this option is set, XBoard communicates with the ICS through
              the  given  character  I/O  device  instead  of  opening  a  TCP
              connection.   Use  this  option if your system does not have any
              kind of Internet connection itself  (not  even  a  SLIP  or  PPP
              connection),  but  you  do  have  dial-up access (or a hardwired
              terminal line) to an Internet service provider  from  which  you
              can telnet to the ICS.

              The  support  for  this option in XBoard is minimal. You need to
              set all communication parameters and tty modes before you  enter
              XBoard.

              Use a script something like this:

                  stty raw -echo 9600 > /dev/tty00
                  xboard -ics -icscomm /dev/tty00

              Here  replace ‘/dev/tty00’ with the name of the device that your
              modem is connected to.  You  might  have  to  add  several  more
              options to these stty commands. See the man pages for ‘stty’ and
              ‘tty’ if you run into problems. Also, on many systems stty works
              on its standard input instead of standard output, so you have to
              use ‘<’ instead of ‘>’.

              If you are using linux, try  starting  with  the  script  below.
              Change it as necessary for your installation.

                  #!/bin/sh -f
                  # configure modem and fire up XBoard

                  # configure modem
                  (
                    stty 2400 ; stty raw ; stty hupcl ; stty -clocal
                    stty ignbrk ; stty ignpar ; stty ixon ; stty ixoff
                    stty -iexten ; stty -echo
                  ) < /dev/modem
                  xboard -ics -icscomm /dev/modem

              After  you  start XBoard in this way, type whatever commands are
              necessary to dial out to your  Internet  provider  and  log  in.
              Then  telnet  to ICS, using a command like ‘telnet chessclub.com
              5000’.  Important: See the paragraph below about  extra  echoes,
              in Limitations.

       -icslogon or -internetChessServerLogonScript file-name
              Whenever  XBoard  connects  to  the Internet Chess Server, if it
              finds a file with the name given in this option,  it  feeds  the
              file’s contents to the ICS as commands. The default file name is
              ‘.icsrc’.  Usually the first two lines of  the  file  should  be
              your  ICS  user  name  and  password.  The file can be either in
              $CHESSDIR, in XBoard’s working directory if CHESSDIR is not set,
              or in your home directory.

       -msLoginDelay delay
              If  you  experience  trouble logging on to an ICS when using the
              ‘-icslogon’ option, inserting some delay between  characters  of
              the logon script may help. This option adds ‘delay’ milliseconds
              of delay between characters. Good values to try are 100 and 250.

       -icsinput/-xicsinput or -internetChessServerInputBox true/false
              Sets  the  ICS  Input  Box  menu option. See Mode Menu. Default:
              false.

       -autocomm/-xautocomm or -autoComment true/false
              Sets the Auto Comment menu option. See  Options  Menu.  Default:
              false.

       -autoflag/-xautoflag or -autoCallFlag true/false
              Sets  the  Auto  Flag  menu  option.  See Options Menu. Default:
              false.

       -autobs/-xautobs or -autoObserve true/false
              Sets the Auto Observe menu option.  See Options  Menu.  Default:
              false.

       -autoKibitz
              Enables  kibitzing  of  the engines last thinking output (depth,
              score, time, speed, PV) before it moved to  the  ICS,  in  zippy
              mode.  The  option  ‘showThinking’  must be switched on for this
              option to work.  Also diverts similar kibitz information  of  an
              opponent  engine  that  is  playing  you  through the ICS to the
              engine-output window, as if the engine was playing locally.

       -moves/-xmoves or -getMoveList true/false
              Sets the Get Move List menu option.  See Options Menu.  Default:
              true.

       -alarm/-xalarm or -icsAlarm true/false
              Sets  the  ICS  Alarm  menu  option.  See Options Menu. Default:
              true.

       -icsAlarmTime ms
              Sets the time in milliseconds for the  ICS  Alarm  menu  option.
              See Options Menu. Default: 5000.

       lowTimeWarning true/false
              Controls  a  color change of the board as a warning your time is
              running out.  See Options Menu. Default: false.

       -pre/-xpre or -premove true/false
              Sets the Premove menu option. See Options Menu. Default: true.

       -quiet/-xquiet or -quietPlay true/false
              Sets the Quiet Play menu option.  See  Options  Menu.   Default:
              false.

       -colorizeMessages or -colorize
              Setting  colorizeMessages  to  true tells XBoard to colorize the
              messages received from the ICS.  Colorization works only if your
              xterm  supports  ISO  6429  escape  sequences  for changing text
              colors.

       -colorShout foreground,background,bold
       -colorSShout foreground,background,bold
       -colorChannel1 foreground,background,bold
       -colorChannel foreground,background,bold
       -colorKibitz foreground,background,bold
       -colorTell foreground,background,bold
       -colorChallege foreground,background,bold
       -colorRequest foreground,background,bold
       -colorSeek foreground,background,bold
       -colorNormal foreground,background,bold
              These options set the colors used when colorizing ICS  messages.
              All  ICS  messages  are  grouped  into  one of these categories:
              shout,  sshout,  channel  1,  other   channel,   kibitz,   tell,
              challenge,  request  (including abort, adjourn, draw, pause, and
              takeback), or normal (all other messages).

              Each foreground  or  background  argument  can  be  one  of  the
              following:  black,  red,  green,  yellow,  blue,  magenta, cyan,
              white,  or  default.   Here  ‘‘default’’   means   the   default
              foreground  or background color of your xterm.  Bold can be 1 or
              0.  If background is omitted, ‘‘default’’ is assumed; if bold is
              omitted, 0 is assumed.

              Here   is   an  example  of  how  to  set  the  colors  in  your
              ‘.Xresources’ file.  The  colors  shown  here  are  the  default
              values;  you  will  get  them if you turn ‘-colorize’ on without
              specifying your own colors.

                  xboard*colorizeMessages: true
                  xboard*colorShout: green
                  xboard*colorSShout: green, black, 1
                  xboard*colorChannel1: cyan
                  xboard*colorChannel: cyan, black, 1
                  xboard*colorKibitz: magenta, black, 1
                  xboard*colorTell: yellow, black, 1
                  xboard*colorChallenge: red, black, 1
                  xboard*colorRequest: red
                  xboard*colorSeek: blue
                  xboard*colorNormal: default

       -soundProgram progname
              If this option  is  set  to  a  sound-playing  program  that  is
              installed  and  working  on  your  system, XBoard can play sound
              files when certain events  occur,  listed  below.   The  default
              program  name  is "play".  If any of the sound options is set to
              "$", the event rings the terminal bell by sending a ^G character
              to  standard  output,  instead  of  playing a sound file.  If an
              option is set to the empty string "", no  sound  is  played  for
              that event.

       -soundShout filename
       -soundSShout filename
       -soundChannel filename
       -soundKibitz filename
       -soundTell filename
       -soundChallenge filename
       -soundRequest filename
       -soundSeek filename
              These  sounds  are triggered in the same way as the colorization
              events described above.  They all default to "", no sound.  They
              are played only if the colorizeMessages is on.

       -soundMove filename
              This sound is used by the Move Sound menu option.  Default: "$".

       -soundIcsAlarm filename
              This sound is used by the ICS Alarm menu option.  Default:  "$".

       -soundIcsWin filename
              This  sound is played when you win an ICS game.  Default: "" (no
              sound).

       -soundIcsLoss filename
              This sound is played when you lose an ICS game.  Default: "" (no
              sound).

       -soundIcsDraw filename
              This sound is played when you draw an ICS game.  Default: "" (no
              sound).

       -soundIcsUnfinished filename
              This sound is played when an ICS game that you are participating
              in  is  aborted,  adjourned,  or  otherwise ends inconclusively.
              Default: "" (no sound).

              Here  is  an  example  of  how  to  set  the  sounds   in   your
              ‘.Xresources’ file:

                  xboard*soundShout: shout.wav
                  xboard*soundSShout: sshout.wav
                  xboard*soundChannel1: channel1.wav
                  xboard*soundChannel: channel.wav
                  xboard*soundKibitz: kibitz.wav
                  xboard*soundTell: tell.wav
                  xboard*soundChallenge: challenge.wav
                  xboard*soundRequest: request.wav
                  xboard*soundSeek: seek.wav
                  xboard*soundMove: move.wav
                  xboard*soundIcsWin: win.wav
                  xboard*soundIcsLoss: lose.wav
                  xboard*soundIcsDraw: draw.wav
                  xboard*soundIcsUnfinished: unfinished.wav
                  xboard*soundIcsAlarm: alarm.wav

   Load and Save options
       -lgf or -loadGameFile file
       -lgi or -loadGameIndex index
              If  the ‘loadGameFile’ option is set, XBoard loads the specified
              game file at startup. The file name ‘-’ specifies  the  standard
              input.  If  there is more than one game in the file, XBoard pops
              up a menu of the available games, with entries  based  on  their
              PGN  (Portable  Game  Notation)  tags.   If  the ‘loadGameIndex’
              option is set to ‘N’, the menu is suppressed and the N  th  game
              found  in  the  file  is  loaded  immediately.  The menu is also
              suppressed if ‘matchMode’ is enabled or if the game  file  is  a
              pipe;  in  these  cases  the  first  game  in the file is loaded
              immediately.  Use  the  ‘pxboard’  shell  script  provided  with
              XBoard  if  you  want to pipe in files containing multiple games
              and still see the menu.  If the loadGameIndex specifies an index
              -1,  this  triggers  auto-increment of the index in ‘matchMode’,
              which means that after every game the index  is  incremented  by
              one,  causing  each game of the match to be played from the next
              game in the file. Similarly, specifying an  index  value  of  -2
              causes the index to be incremented every two games, so that each
              game in the file is used  twice  (with  reversed  colors).   The
              ‘rewindIndex’  option  causes the index to be reset to the first
              game of the file when it has reached a specified value.

       -rewindIndex n
              Causes a position file  or  game  file  to  be  rewound  to  its
              beginning   after   n   positions  or  games  in  auto-increment
              ‘matchMode’.   See  ‘loadPositionIndex’   and   ‘loadGameIndex’.
              default: 0 (no rewind).

       -td or -timeDelay seconds
              Time  delay between moves during ‘Load Game’. Fractional seconds
              are allowed; try ‘-td 0.4’. A  time  delay  value  of  -1  tells
              XBoard  not to step through game files automatically. Default: 1
              second.

       -sgf or -saveGameFile file
              If this option is set, XBoard appends a  record  of  every  game
              played  to  the  specified file. The file name ‘-’ specifies the
              standard output.

       -autosave/-xautosave or -autoSaveGames true/false
              Sets the Auto Save menu option.   See  Options  Menu.   Default:
              false.  Ignored if ‘saveGameFile’ is set.

       -lpf or -loadPositionFile file
       -lpi or -loadPositionIndex index
              If  the  ‘loadPositionFile’  option  is  set,  XBoard  loads the
              specified position file at startup. The file name ‘-’  specifies
              the  standard input. If the ‘loadPositionIndex’ option is set to
              N, the Nth position found in the file is loaded;  otherwise  the
              first position is loaded.  If the loadPositionIndex specifies an
              index  -1,  this  triggers  auto-increment  of  the   index   in
              ‘matchMode’,  which  means  that  after  every game the index is
              incremented by one, causing each game of the match to be  played
              from  the  next  position  in the file. Similarly, specifying an
              index value of -2 causes the index to be incremented  every  two
              games, so that each position in the file is used twice (with the
              engines playing  opposite  colors).   The  ‘rewindIndex’  option
              causes  the  index to be reset to the first position of the file
              when it has reached a specified value.

       -spf or -savePositionFile file
              If this option is set, XBoard appends the final position reached
              in  every  game  played to the specified file. The file name ‘-’
              specifies the standard output.

       -pgnExtendedInfo true/false
              If this option is set, XBoard saves depth, score and  time  used
              for  each  move  that  the  engine found as a comment in the PGN
              file.  Default: false.

       -pgnEventHeader string
              Sets the name used in the PGN event  tag  to  string.   Default:
              "Computer Chess Game".

       -saveOutOfBookInfo true/false
              Include  the  information  on  how the engine(s) game out of its
              opening book in a special ’annotator’ tag with the PGN file.

       -oldsave/-xoldsave or -oldSaveStyle true/false
              Sets  the  Old  Save  Style  menu  option.   See  Options  Menu.
              Default: false.

       -gameListTags string
              The  character  string lists the PGN tags that should be printed
              in the Game List, and their order. The meaning of the  codes  is
              e=event,  s=site,  d=date, o=round, p=players, r=result, w=white
              Elo, b=black Elo, t=time control, v=variant, a=out-of-book info.
              Default: "eprd"

   User interface options
       -display
       -geometry
       -iconic
              These and most other standard Xt options are accepted.

       -noGUI Suppresses  all  GUI  functions of XBoard (to speed up automated
              ultra-fast engine-engine games, which you dont want  to  watch).
              There  will  be no board or clock updates, no printing of moves,
              and no update of the icon on the task bar in this mode.

       -movesound/-xmovesound or -ringBellAfterMoves true/false
              Sets the Move Sound menu option.  See  Options  Menu.   Default:
              false.  For compatibility with old XBoard versions, -bell/-xbell
              are also accepted as abbreviations for this option.

       -exit/-xexit or -popupExitMessage true/false
              Sets the Popup Exit Message  menu  option.   See  Options  Menu.
              Default: true.

       -popup/-xpopup or -popupMoveErrors true/false
              Sets  the  Popup  Move  Errors  menu  option.  See Options Menu.
              Default: false.

       -queen/-xqueen or -alwaysPromoteToQueen true/false
              Sets the Always Queen menu option.  See Options Menu.   Default:
              false.

       -legal/-xlegal or -testLegality true/false
              Sets the Test Legality menu option.  See Options Menu.  Default:
              true.

       -size or -boardSize (sizeName | n1,n2,n3,n4,n5,n6,n7)
              Determines how large the board will be, by selecting  the  pixel
              size  of  the  pieces and setting a few related parameters.  The
              sizeName can be one of: Titanic, giving  129x129  pixel  pieces,
              Colossal  116x116,  Giant  108x108, Huge 95x95, Big 87x87, Large
              80x80, Bulky 72x72, Medium 64x64, Moderate 58x58, Average 54x54,
              Middling  49x49, Mediocre 45x45, Small 40x40, Slim 37x37, Petite
              33x33, Dinky 29x29, Teeny 25x25, or Tiny 21x21.  Pieces  of  all
              these  sizes  are built into XBoard.  Other sizes can be used if
              you have  them;  see  the  pixmapDirectory  and  bitmapDirectory
              options.   The default depends on the size of your screen; it is
              approximately the largest size that will fit without clipping.

              You can select other sizes or vary other  layout  parameters  by
              providing  a  list of comma-separated values (with no spaces) as
              the argument.  You do not need to provide all  the  values;  for
              any  you  omit from the end of the list, defaults are taken from
              the nearest built-in size.  The value ‘n1’ gives the piece size,
              ‘n2’  the  width  of  the black border between squares, ‘n3’ the
              desired size for the clockFont, ‘n4’ the desired  size  for  the
              coordFont,  ‘n5’ the desired size for the default font, ‘n6’ the
              smallLayout flag (0 or 1), and ‘n7’ the tinyLayout  flag  (0  or
              1).   All  dimensions  are  in  pixels.   If  the border between
              squares is eliminated (0 width), the various  highlight  options
              will  not  work,  as there is nowhere to draw the highlight.  If
              smallLayout is 1 and ‘titleInWindow’ is true, the window  layout
              is rearranged to make more room for the title.  If tinyLayout is
              1, the labels on the menu bar are abbreviated to  one  character
              each and the buttons in the button bar are made narrower.

       -coords/-xcoords or -showCoords true/false
              Sets  the  Show Coords menu option.  See Options Menu.  Default:
              false.  The ‘coordFont’ option specifies what font to use.

       -autoraise/-xautoraise or -autoRaiseBoard true/false
              Sets the Auto  Raise  Board  menu  option.   See  Options  Menu.
              Default: true.

       -autoflip/-xautoflip or -autoFlipView true/false
              Sets  the  Auto  Flip  View  menu  option.   See  Options  Menu.
              Default: true.

       -flip/-xflip or -flipView true/false
              If Auto Flip View is not set, or if you are  observing  but  not
              participating  in  a  game, then the positioning of the board at
              the start of each game  depends  on  the  flipView  option.   If
              flipView is false (the default), the board is positioned so that
              the white pawns move from the bottom to the top;  if  true,  the
              black  pawns  move from the bottom to the top.  In any case, the
              Flip menu option (see Options Menu) can  be  used  to  flip  the
              board after the game starts.

       -title/-xtitle or -titleInWindow true/false
              If  this  option  is true, XBoard displays player names (for ICS
              games) and game file names (for ‘Load  Game’)  inside  its  main
              window.  If  the option is false (the default), this information
              is displayed only in the window banner. You probably won’t  want
              to  set  this option unless the information is not showing up in
              the banner, as happens with a few X window managers.

       -buttons/-xbuttons or -showButtonBar True/False
              If this option is False, xboard omits the [<<] [<] [P] [>]  [>>]
              button  bar  from  the  window,  allowing the message line to be
              wider.  You can still get the functions of these  buttons  using
              the menus or their keyboard shortcuts.  Default: true.

       -mono/-xmono or -monoMode true/false
              Determines  whether  XBoard displays its pieces and squares with
              two colors (true) or four (false). You shouldn’t have to specify
              ‘monoMode’; XBoard will determine if it is necessary.

       -flashCount count
       -flashRate rate
       -flash/-xflash
              These  options enable flashing of pieces when they land on their
              destination square.  ‘flashCount’ tells XBoard how many times to
              flash  a  piece  after  it  lands  on  its  destination  square.
              ‘flashRate’  controls  the  rate  of   flashing   (flashes/sec).
              Abbreviations:  ‘flash’  sets  flashCount  to  3.  ‘xflash’ sets
              flashCount  to  0.   Defaults:   flashCount=0   (no   flashing),
              flashRate=5.

       -highlight/-xhighlight or -highlightLastMove true/false
              Sets  the  Highlight  Last  Move  menu option. See Options Menu.
              Default: false.

       -blind/-xblind or -blindfold true/false
              Sets the Blindfold menu option.   See  Options  Menu.   Default:
              false.

       -clockFont font
              The  font  used for the clocks. If the option value is a pattern
              that does not specify the font size, XBoard tries to  choose  an
              appropriate  font  for  the  board  size  being  used.  Default:
              -*-helvetica-bold-r-normal--*-*-*-*-*-*-*-*.

       -coordFont font
              The  font  used  for  rank  and  file   coordinate   labels   if
              ‘showCoords’ is true. If the option value is a pattern that does
              not specify the font size, XBoard tries to choose an appropriate
              font for the board size being used.  Default: -*-helvetica-bold-
              r-normal--*-*-*-*-*-*-*-*.

       -font font
              The font used for popup dialogs, menus, comments, etc.   If  the
              option  value  is a pattern that does not specify the font size,
              XBoard tries to choose an appropriate font for  the  board  size
              being        used.         Default:       -*-helvetica-medium-r-
              normal--*-*-*-*-*-*-*-*.

       -fontSizeTolerance tol
              In the font selection algorithm,  a  nonscalable  font  will  be
              preferred  over  a  scalable font if the nonscalable font’s size
              differs by ‘tol’ pixels or less from the desired size.  A  value
              of -1 will force a scalable font to always be used if available;
              a value of 0 will use a nonscalable font only if it  is  exactly
              the   right  size;  a  large  value  (say  1000)  will  force  a
              nonscalable font to always be used if available.  Default: 4.

       -bm or -bitmapDirectory dir
       -pixmap or -pixmapDirectory dir
              These options control what piece images xboard uses.  The XBoard
              distribution includes one set of pixmap pieces in xpm format, in
              the directory ‘pixmaps’, and one set of  bitmap  pieces  in  xbm
              format, in the directory ‘bitmaps’.  Pixmap pieces give a better
              appearance on the screen: the white pieces  have  dark  borders,
              and  the  black  pieces  have  opaque  internal  details.   With
              bitmaps, neither piece color has  a  border,  and  the  internal
              details  are  transparent;  you  see  the  square color or other
              background color through them.

              If XBoard is configured and compiled on a system  that  includes
              libXpm, the X pixmap library, the xpm pixmap pieces are compiled
              in as the default.  A different xpm piece set can be selected at
              runtime with the ‘pixmapDirectory’ option, or a bitmap piece set
              can be selected with the ‘bitmapDirectory’ option.

              If XBoard is configured and compiled on a system that  does  not
              include  libXpm  (or  the ‘--disable-xpm’ option is given to the
              configure program), the bitmap pieces are  compiled  in  as  the
              default.  It is not possible to use xpm pieces in this case, but
              pixmap pieces in another format called  "xim"  can  be  used  by
              giving  the  ‘pixmapDirectory’  option.   Or  again, a different
              bitmap piece set can  be  selected  with  the  ‘bitmapDirectory’
              option.

              Files  in  the  ‘bitmapDirectory’  must be named as follows: The
              first character of a  piece  bitmap  name  gives  the  piece  it
              represents   (‘p’,  ‘n’,  ‘b’,  ‘r’,  ‘q’,  or  ‘k’),  the  next
              characters give the size  in  pixels,  the  following  character
              indicates  whether  the  piece is solid or outline (‘s’ or ‘o’),
              and the extension is ‘.bm’.  For example, a solid  80x80  knight
              would  be named ‘n80s.bm’.  The outline bitmaps are used only in
              monochrome mode.  If bitmap  pieces  are  compiled  in  and  the
              bitmapDirectory  is  missing  some files, the compiled in pieces
              are used instead.

              If the bitmapDirectory option is given, it is also  possible  to
              replace  xboard’s  icons  and menu checkmark, by supplying files
              named ‘icon_white.bm’, ‘icon_black.bm’, and ‘checkmark.bm’.

              For  more  information  about  pixmap  pieces  and  how  to  get
              additional sets, see zic2xpm below.

       -whitePieceColor color
       -blackPieceColor color
       -lightSquareColor color
       -darkSquareColor color
       -highlightSquareColor color
       -lowTimeWarningColor color
              Colors  to  use  for the pieces, squares, and square highlights.
              Defaults:

                  -whitePieceColor       #FFFFCC
                  -blackPieceColor       #202020
                  -lightSquareColor      #C8C365
                  -darkSquareColor       #77A26D
                  -highlightSquareColor  #FFFF00
                  -premoveHighlightColor #FF0000
                  -lowTimeWarningColor   #FF0000

              On a grayscale monitor you might prefer:

                  -whitePieceColor       gray100
                  -blackPieceColor       gray0
                  -lightSquareColor      gray80
                  -darkSquareColor       gray60
                  -highlightSquareColor  gray100
                  -premoveHighlightColor gray70
                  -lowTimeWarningColor   gray70

       -drag/-xdrag or -animateDragging true/false
              Sets  the  Animate  Dragging  menu  option.  See  Options  Menu.
              Default: true.

       -animate/-xanimate or -animateMoving true/false
              Sets the Animate Moving menu option. See Options Menu.  Default:
              true.

       -animateSpeed n
              Number of milliseconds delay between each animation  frame  when
              Animate Moves is on.

       -autoDisplayComment true/false
       -autoDisplayTags true/false
              If  set  to  true,  these options cause the window with the move
              comments, and the window with PGN tags, respectively, to pop  up
              automatically  when such tags or comments are encountered during
              the replaying a stored or loaded game.  Default: true.

       -pasteSelection true/false
              If this option is set to true, the Paste Position and Paste Game
              options  paste from the currently selected text.  If false, they
              paste from the clipboard.  Default: false.

   Adjudication Options
       -adjudicateLossThreshold n
              If the given value is non-zero, XBoard adjudicates the game as a
              loss  if  both engines agree for a duration of 6 consecutive ply
              that the score is below  the  given  score  threshold  for  that
              engine.  Make  sure the score is interpreted properly by XBoard,
              using  ‘-firstScoreAbs’   and   ‘-secondScoreAbs’   if   needed.
              Default: 0 (no adjudication)

       -adjudicateDrawMoves n
              If the given value is non-zero, XBoard adjudicates the game as a
              draw if after the given number of moves it was not yet  decided.
              Default: 0 (no adjudication)

       -checkMates true/false
              If  this  option  is  set,  XBoard  detects  all  checkmates and
              stalemates, and ends the game as soon as they occur.   Legality-
              testing  must  be switched on for this option to work.  Default:
              true

       -testClaims true/false
              If this option is set, XBoard verifies all result claims made by
              engines,  and  those who send false claims will forfeit the game
              because of it.  Legality-testing must be switched  on  for  this
              option to work. Default: true

       -materialDraws true/false
              If  this  option  is set, XBoard adjudicates games as draws when
              there is no sufficient material left  to  inflict  a  checkmate.
              This  applies  to KBKB with like bishops (any number, actually),
              and to KBK, KNK and KK.  Legality-testing must  be  switched  on
              for this option to work. Default: true

       -trivialDraws true/false
              If  this  option  is set, XBoard adjudicates games as draws that
              cannot be usually won without opponent cooperation. This applies
              to  KBKB  with unlike bishops, and to KBKN, KNKN, KNNK, KRKR and
              KQKQ. The draw is called after 6 ply into  these  end-games,  to
              allow  quick  mates that can occur in some exceptional positions
              to be found by the engines.  KQKQ does not really belong in this
              category,  and might be taken out in the future.  (When bitbase-
              based adjudications are implemented.)  Legality-testing must  be
              on for this option to work. Default: false

       -ruleMoves n
              If the given value is non-zero, XBoard adjudicates the game as a
              draw after the given number  of  consecutive  reversible  moves.
              Engine   draw   claims  are  always  accepted  after  50  moves,
              irrespective of the given value of n.

       -repeatsToDraw n
              If the given value is non-zero, xboard adjudicates the game as a
              draw  if  a  position  is  repeated  the  given number of times.
              Engines draw claims are always accepted after 3 repeats, (on the
              3rd  occurrence,  actually),  irrespective  of  the  value of n.
              Beware that positions that have different castling or en-passant
              rights  do  not  count  as  repeats,  XBoard  is  fully e.p. and
              castling aware!

   Other options
       -ncp/-xncp or -noChessProgram true/false
              If this option is true, XBoard acts as a passive chessboard;  it
              does  not  start  a  chess engine at all. Turning on this option
              also turns off clockMode. Default: false.

       -mode or -initialMode modename
              If this option is given, XBoard selects the given modename  from
              the  Mode menu after starting and (if applicable) processing the
              loadGameFile  or  loadPositionFile  option.  Default:   ""   (no
              selection).     Other   supported   values   are   MachineWhite,
              MachineBlack,  TwoMachines,  Analysis,  AnalyzeFile,   EditGame,
              EditPosition, and Training.

       -variant varname
              Activates   preliminary,   partial  support  for  playing  chess
              variants against a local engine or editing variant games.   This
              flag is not needed in ICS mode.  Recognized variant names are:

                  normal        Normal chess
                  wildcastle    Shuffle chess, king can castle from d file
                  nocastle      Shuffle chess, no castling allowed
                  fischerandom  Fischer Random shuffle chess
                  bughouse      Bughouse, ICC/FICS rules
                  crazyhouse    Crazyhouse, ICC/FICS rules
                  losers        Lose all pieces or get mated (ICC wild 17)
                  suicide       Lose all pieces including king (FICS)
                  giveaway      Try to have no legal moves (ICC wild 26)
                  twokings      Weird ICC wild 9
                  kriegspiel    Opponent’s pieces are invisible
                  atomic        Capturing piece explodes (ICC wild 27)
                  3check        Win by giving check 3 times (ICC wild 25)
                  shatranj      An ancient precursor of chess (ICC wild 28)
                  xiangqi       Chinese Chess (on a 9x10 board)
                  shogi         Japanese Chess (on a 9x9 board & piece drops)
                  capablanca    Capablanca Chess (10x8 board, with Archbishop
                                and Chancellor pieces)
                  gothic        similar, with a better initial position
                  caparandom    An FRC-like version of Capablanca Chess (10x8)
                  janus         A game with two Archbishops (10x8 board)
                  courier       Medieval intermediate between shatranj and
                                modern Chess (on 12x8 board)
                  falcon        Patented 10x8 variant with two Falcon pieces
                  berolina      Pawns capture straight ahead, and move diagonal
                  cylinder      Pieces wrap around the board edge
                  knightmate    King moves as Knight, and vice versa
                  super         Superchess (shuffle variant with 4 exo-pieces)
                  fairy         A catchall variant in which all piece types
                                known to XBoard can participate (8x8)
                  unknown       Catchall for other unknown variants

              NOT  ALL  BOARDSIZES  PROVIDE A COMPLETE SET OF BUILT-IN BITMAPS
              FOR ALL UN-ORTHODOX PIECES, though. Only in ‘boardSize’ middling
              and  bulky  all  22  piece  types are provided, while -boardSize
              petite has most of them. Archbishop, Chancellor and  Amazon  are
              supported  in  every size from petite to bulky. Kings or Amazons
              are substituted for missing bitmaps. You can still play variants
              needing  un-orthodox  pieces in other board sizes providing your
              own bitmaps through the ‘bitmapDirectory’  or  ‘pixmapDirectory’
              options.

              In  the  shuffle  variants,  XBoard now does shuffle the pieces,
              although you can still do it by hand using Edit Position.   Some
              variants are supported only in ICS mode, including bughouse, and
              kriegspiel.  The winning/drawing conditions in crazyhouse  (off-
              board  interposition  on  mate)  are  not  fully understood, but
              losers, suicide, giveaway, atomic,  and  3check  should  be  OK.
              Berolina  and  cylinder  chess  can only be played with legality
              testing off.  In crazyhouse, XBoard now does keep track of  off-
              board  pieces.   In  shatranj  it does implement the baring rule
              when mate detection is switched on.

       -boardHeight N
              Allows you to set a non-standard number of board  ranks  in  any
              variant.   If  the height is given as -1, the default height for
              the variant is used.  Default: -1

       -boardWidth N
              Allows you to set a non-standard number of board  files  in  any
              variant.  If the width is given as -1, the default width for the
              variant  is  used.   With  a  non-standard  width,  the  initial
              position  will  always  be  an empty board, as the usual opening
              array will not fit.  Default: -1

       -holdingsSize N
              Allows you to set a non-standard size for the  holdings  in  any
              variant.   If the size is given as -1, the default holdings size
              for the variant is used.  The first N piece types will  go  into
              the  holdings  on  capture, and you will be able to drop them on
              the board in stead of making a normal move. If  size  equals  0,
              there will be no holdings.  Default: -1

       -defaultFrcPosition N
              Specifies  the  number  of the opening position in shuffle games
              like Chess960.  A value of -1 means  the  position  is  randomly
              generated by XBoard at the beginning of every game.  Default: -1

       -pieceToSquareTable string
              The characters that are used to represent the piece types XBoard
              knows  in FEN diagrams and SAN moves. The string argument has to
              have an even length (or it will be ignored), as white and  black
              pieces  have  to  be  given separately (in that order). The last
              letter for each color will be the King.  The letters before that
              will  be PNBRQ and then a whole host of fairy pieces in an order
              that has not fully crystallized yet (currently FEACWMOHIJGDVSLU,
              F=Ferz,    Elephant,    A=Archbishop,   C=Chancellor,   W=Wazir,
              M=Commoner, O=Cannon, H=Nightrider). You should  list  at  least
              all  pieces  that  occur  in the variant you are playing. If you
              have less than 44 characters  in  the  string,  the  pieces  not
              mentioned  will  get assigned a period, and you will not be able
              to distinguish them in FENs.  You  can  also  explicitly  assign
              pieces  a  period,  in  which  case  they will not be counted in
              deciding which captured pieces can  go  into  the  holdings.   A
              tilde  ’~’  as  a  piece  name  does  mean this piece is used to
              represent a promoted Pawn  in  crazyhouse-like  games,  i.e.  on
              capture  it  turns  back onto a Pawn.  A ’+’ similarly indicates
              the piece is a shogi-style promoted piece, that should revert to
              its  non-promoted  version  on  capture (rather than to a Pawn).
              Note that promoted pieces are represented by pieces  11  further
              in the list.  You should not have to use this option often: each
              variant has its own default setting for the piece representation
              in FEN, which should be sufficient in normal use.  Default: ""

       -debug/-xdebug or -debugMode true/false
              Turns on debugging printout.

       -debugFile filename or -nameOfDebugFile filename
              Sets   the  name  of  the  file  to  which  XBoard  saves  debug
              information  (including  all  communication  to  and  from   the
              engines).

       -engineDebugOutput number
              Specifies  how  XBoard should handle unsolicited output from the
              engine, with respect to saving it in the debug file.  The output
              is  further  (hopefully)  ignored.  If number=0, XBoard refrains
              from writing  such  spurious  output  to  the  debug  file.   If
              number=1,  all  engine output is written faithfully to the debug
              file.  If number=2, any protocol-violating line is prefixed with
              a  ’#’  character,  as  the engine itself should have done if it
              wanted to submit info for inclusion in  the  debug  file.   This
              option  is provided for the benefit of applications that use the
              debug file as a source of information, such as  the  broadcaster
              of  live  games TLCV / TLCS.  Such applications can be protected
              from spurious engine output that might otherwise confuse them.

       -rsh or -remoteShell shell-name
              Name of the command used to run programs remotely.  The  default
              is  ‘rsh’  or  ‘remsh’, determined when XBoard is configured and
              compiled.

       -ruser or -remoteUser user-name
              User name on the remote system when running  programs  with  the
              ‘remoteShell’. The default is your local user name.

       -userName username
              Name  under  which  the  Human  player will be listed in the PGN
              file.  Default is the login name on your local computer.

       -delayBeforeQuit number
       -delayAfterQuit number
              These options specify how long XBoard has to wait before sending
              a termination signal to rogue engine processes, that do not want
              to react to the ’quit’ command. The second  one  determines  the
              pause after killing the engine, to make sure it dies.

CHESS SERVERS

       An  "Internet Chess Server", or "ICS", is a place on the Internet where
       people can get together to play chess, watch other people’s  games,  or
       just chat.  You can use either ‘telnet’ or a client program like XBoard
       to connect to the server.  There are thousands of registered  users  on
       the  different  ICS  hosts,  and  it is not unusual to meet 200 on both
       chessclub.com and freechess.org.

       Most people can just type ‘xboard -ics’  to  start  XBoard  as  an  ICS
       client.  Invoking XBoard in this way connects you to the Internet Chess
       Club (ICC), a commercial ICS.  You can log in there as a guest even  if
       you  do  not  have  a paid account.  To connect to the largest Free ICS
       (FICS), use the command ‘xboard -ics -icshost  freechess.org’  instead,
       or  substitute  a  different host name to connect to your favorite ICS.
       For a  full  description  of  command-line  options  that  control  the
       connection to ICS and change the default values of ICS options, see ICS
       options.

       While you are running XBoard as an ICS client,  you  use  the  terminal
       window  that you started XBoard from as a place to type in commands and
       read information that is not available on the chessboard.

       The first time you need to use the terminal is to enter your login name
       and  password,  if  you  are a registered player. (You don’t need to do
       this manually; the ‘icsLogon’ option  can  do  it  for  you.   See  ICS
       options.)   If  you are not registered, enter ‘g’ as your name, and the
       server will pick a unique guest name for you.

       Some useful ICS commands include

       help <topic>
              to get help on the given <topic>. To  get  a  list  of  possible
              topics  type  "help" without topic.  Try the help command before
              you ask other people on the server for help.

              For example ‘help register’ tells you how to become a registered
              ICS player.

       who <flags>
              to  see  a  list  of  people  who are logged on.  Administrators
              (people you should talk to if you have  a  problem)  are  marked
              with  the  character  ‘*’, an asterisk. The <flags> allow you to
              display only selected players: For example,  ‘who  of’  shows  a
              list of players who are interested in playing but do not have an
              opponent.

       games  to see what games are being played

       match <player> [<mins>] [<inc>]
              to challenge another player to a game. Both opponents get <mins>
              minutes for the game, and <inc> seconds will be added after each
              move.  If another player challenges you, the server asks if  you
              want  to  accept  the  challenge;  use the ‘accept’ or ‘decline’
              commands to answer.

       accept
       decline
              to accept or decline another player’s offer.  The offer  may  be
              to  start  a  new  game,  or  to agree to a ‘draw’, ‘adjourn’ or
              ‘abort’ the current game. See Action Menu.

              If you have more than one pending offer (for  example,  if  more
              than  one  player is challenging you, or if your opponent offers
              both a draw and  to  adjourn  the  game),  you  have  to  supply
              additional   information,   by  typing  something  like  ‘accept
              <player>’, ‘accept draw’, or ‘draw’.

       draw
       adjourn
       abort  asks your opponent to terminate  a  game  by  mutual  agreement.
              Adjourned  games  can  be  continued  later.   Your opponent can
              either ‘decline’ your offer or accept it  (by  typing  the  same
              command  or typing ‘accept’).  In some cases these commands work
              immediately,  without  asking  your  opponent  to  agree.    For
              example, you can abort the game unilaterally if your opponent is
              out of time, and you can claim  a  draw  by  repetition  or  the
              50-move rule if available simply by typing ‘draw’.

       finger <player>
              to   get   information   about  the  given  <player>.  (Default:
              yourself.)

       vars   to get a list of personal settings

       set <var> <value>
              to modify these settings

       observe <player>
              to observe an ongoing game of the given <player>.

       examine
       oldmoves
              to review a recently completed game

       Some special XBoard features are activated when you are in examine mode
       on   ICS.   See  the  descriptions  of  the  menu  commands  ‘Forward’,
       ‘Backward’, ‘Pause’, ‘ICS Client’, and ‘Stop  Examining’  on  the  Step
       Menu, Mode Menu, and Options Menu.

FIREWALLS

       By  default,  XBoard  communicates  with  an  Internet  Chess Server by
       opening a TCP socket directly from the machine it is running on to  the
       ICS.  If  there  is  a  firewall between your machine and the ICS, this
       won’t work. Here are some recipes for getting around  common  kinds  of
       firewalls   using  special  options  to  XBoard.   Important:  See  the
       paragraph in the below about extra echoes, in Limitations.

       Suppose that you can’t telnet directly to ICS, but you can telnet to  a
       firewall  host,  log  in, and then telnet from there to ICS.  Let’s say
       the firewall is called ‘firewall.example.com’. Set command-line options
       as follows:

           xboard -ics -icshost firewall.example.com -icsport 23

       Or in your ‘.Xresources’ file:

           XBoard*internetChessServerHost: firewall.example.com
           XBoard*internetChessServerPort: 23

       Then when you run XBoard in ICS mode, you will be prompted to log in to
       the firewall host. This works because port 23 is  the  standard  telnet
       login  service. Do so, then telnet to ICS, using a command like ‘telnet
       chessclub.com 5000’, or whatever  command  the  firewall  provides  for
       telnetting to port 5000.

       If  your  firewall  lets  you  telnet  (or  rlogin) to remote hosts but
       doesn’t let you telnet to port 5000, you may be able to connect to  the
       chess  server  on port 23 instead, which is the port the telnet program
       uses  by  default.   Some  chess  servers   support   this   (including
       chessclub.com and freechess.org), while some do not.

       If  your  chess  server  does not allow connections on port 23 and your
       firewall does not allow you to connect to other ports, you may be  able
       to  connect  by  hopping through another host outside the firewall that
       you have an account on.  For instance, suppose you have a shell account
       at  ‘foo.edu’.  Follow  the recipe above, but instead of typing ‘telnet
       chessclub.com 5000’ to the firewall, type ‘telnet foo.edu’ (or  ‘rlogin
       foo.edu’), log in there, and then type ‘telnet chessclub.com 5000’.

       Suppose  that  you can’t telnet directly to ICS, but you can use rsh to
       run programs on a firewall host, and  that  host  can  telnet  to  ICS.
       Let’s  say  the  firewall is called ‘rsh.example.com’. Set command-line
       options as follows:

           xboard -ics -gateway rsh.example.com -icshost chessclub.com

       Or in your ‘.Xresources’ file:

           XBoard*gateway: rsh.example.com
           XBoard*internetChessServerHost: chessclub.com

       Then when you run XBoard in ICS mode, it will connect  to  the  ICS  by
       using  ‘rsh’  to  run  the  command ‘telnet chessclub.com 5000’ on host
       ‘rsh.example.com’.

       Suppose that you can telnet anywhere you want, but you have  to  run  a
       special program called ‘ptelnet’ to do so.

       First,  we’ll  consider  the easy case, in which ‘ptelnet chessclub.com
       5000’ gets you to the chess server.  In  this  case  set  command  line
       options as follows:

           xboard -ics -telnet -telnetProgram ptelnet

       Or in your ‘.Xresources’ file:

           XBoard*useTelnet: true
           XBoard*telnetProgram: ptelnet

       Then  when  you  run  XBoard  in  ICS  mode,  it will issue the command
       ‘ptelnet chessclub.com 5000’ to connect to the ICS.

       Next, suppose that ‘ptelnet chessclub.com 5000’ doesn’t work; that  is,
       your ‘ptelnet’ program doesn’t let you connect to alternative ports. As
       noted above, your chess server may allow you  to  connect  on  port  23
       instead.   In that case, just add the option ‘-icsport ""’ to the above
       command, or add ‘XBoard*internetChessServerPort:’ to your ‘.Xresources’
       file.  But if your chess server doesn’t let you connect on port 23, you
       will have to find some other host outside the firewall and hop  through
       it.  For  instance,  suppose you have a shell account at ‘foo.edu’. Set
       command line options as follows:

           xboard -ics -telnet -telnetProgram ptelnet -icshost foo.edu -icsport ""

       Or in your ‘.Xresources’ file:

           XBoard*useTelnet: true
           XBoard*telnetProgram: ptelnet
           XBoard*internetChessServerHost: foo.edu
           XBoard*internetChessServerPort:

       Then when you run XBoard  in  ICS  mode,  it  will  issue  the  command
       ‘ptelnet  foo.edu’  to  connect  to  your  account at ‘foo.edu’. Log in
       there, then type ‘telnet chessclub.com 5000’.

       ICC timestamp and FICS timeseal do not  work  through  some  firewalls.
       You  can  use  them  only if your firewall gives a clean TCP connection
       with a full 8-bit wide path.  If your firewall allows you  to  get  out
       only  by  running  a special telnet program, you can’t use timestamp or
       timeseal across it.  But if you have access to a computer just  outside
       your  firewall,  and  you  have  much lower netlag when talking to that
       computer than to the ICS, it  might  be  worthwhile  running  timestamp
       there.   Follow  the  instructions  above  for  hopping  through a host
       outside the firewall (foo.edu in the example),  but  run  timestamp  or
       timeseal on that host instead of telnet.

       Suppose that you have a SOCKS firewall that will give you a clean 8-bit
       wide  TCP  connection  to  the  chess  server,  but  only   after   you
       authenticate  yourself via the SOCKS protocol.  In that case, you could
       make a socksified version of XBoard and run that.   If  you  are  using
       timestamp or timeseal, you will to socksify it, not XBoard; this may be
       difficult seeing that ICC and FICS do not provide source code for these
       programs.  Socksification is beyond the scope of this document, but see
       the SOCKS Web site at http://www.socks.permeo.com/.  If you are missing
       SOCKS, try http://www.funbureau.com/.

ENVIRONMENT VARIABLES

       Game  and  position  files  are  found  in  a  directory  named  by the
       ‘CHESSDIR’ environment variable. If  this  variable  is  not  set,  the
       current  working  directory  is  used.  If  ‘CHESSDIR’  is  set, XBoard
       actually changes its working directory to  ‘$CHESSDIR’,  so  any  files
       written by the chess engine will be placed there too.

LIMITATIONS AND KNOWN BUGS

       There  is  no  way for two people running copies of XBoard to play each
       other without going through an Internet Chess Server.

       Under some circumstances, your ICS password may be echoed when you  log
       on.

       If  you  are  connecting  to  the  ICS by running telnet on an Internet
       provider or firewall host, you may find that  each  line  you  type  is
       echoed  back  an  extra  time  after  you hit <Enter>. If your Internet
       provider is a Unix system, you can probably turn its echo off by typing
       ‘stty  -echo’  after  you  log  in,  and/or  typing <^E><Enter> (Ctrl+E
       followed by the Enter key) to the telnet program after you have  logged
       into  ICS.   It is a good idea to do this if you can, because the extra
       echo can occasionally confuse XBoard’s parsing routines.

       The game parser recognizes only algebraic notation.

       Many of the following points used to be limitations in XBoard 4.2.7 and
       earlier, but are now fixed: The internal move legality tester in XBoard
       4.3.xx does look at the game history, and is fully aware of castling or
       en-passant-capture  rights.  It permits castling with the king on the d
       file because this is possible in some  "wild  1"  games  on  ICS.   The
       piece-drop  menu  does  not check piece drops in bughouse to see if you
       actually hold the piece you  are  trying  to  drop.  But  this  way  of
       dropping  pieces  should  be  considered  an obsolete feature, now that
       pieces can be dropped by dragging them from the holdings to the  board.
       Anyway,  if you would attempt an illegal move when using a chess engine
       or the ICS, XBoard will accept the error message that comes back,  undo
       the  move,  and  let you try another.  FEN positions saved by XBoard do
       include correct information about whether castling or  en  passant  are
       legal, and also handle the 50-move counter.  The mate detector does not
       understand that non-contact mate is not really mate in  bughouse.   The
       only problem this causes while playing is minor: a "#" (mate indicator)
       character will show up after a non-contact  mating  move  in  the  move
       list.  XBoard  will not assume the game is over at that point, not even
       when the option Detect Mates is on.  Edit Game  mode  always  uses  the
       rules  of  the selected variant, which can be a variant that uses piece
       drops.  You can load and edit games  that  contain  piece  drops.   The
       (obsolete)  piece menus are not active, but you can perform piece drops
       by dragging pieces from the holdings.   Edit  Position  mode  does  not
       allow  you  to  edit the crazyhouse holdings properly.  You cannot drag
       pieces to the holding, and using the popup menu  to  put  pieces  there
       does  not  adapt the holding counts and leads to an inconsistent state.
       Set up crazyhouse positions by loading / pasting a bFEN, from there you
       can  set  the  holdings.   Fischer Random castling is fully understood.
       You can enter castlings by dragging the King on top of your Rook.   You
       can  probably  also  play  Fischer Random successfully on ICS by typing
       castling moves into the ICS Interaction window.

       The menus may not work if your keyboard is in Caps  Lock  or  Num  Lock
       mode.   This  seems to be a problem with the Athena menu widget, not an
       XBoard bug.

       Also see the ToDo file included with the distribution  for  many  other
       possible  bugs,  limitations,  and ideas for improvement that have been
       suggested.

REPORTING PROBLEMS

       You can report bugs and problems with XBoard using the bug  tracker  at
       ‘https://savannah.gnu.org/projects/xboard/’   or  by  sending  mail  to
       ‘<bug-xboard@gnu.org>’.  It can also be useful  to  report  or  discuss
       bugs  in  the  WinBoard  Forum at ‘http://www.open-aurec.com/wbforum/’,
       WinBoard development section.

       Please use the ‘script’ program to start a typescript, run XBoard  with
       the ‘-debug’ option, and include the typescript output in your message.
       Also tell us what kind of machine and what operating system version you
       are using.  The command ‘uname -a’ will often tell you this.

       If you improve XBoard, please send a message about your changes, and we
       will get in touch with you about merging them in to the  main  line  of
       development.

AUTHORS AND CONTRIBUTORS

       Chris  Sears  and  Dan  Sears  wrote  the  original  XBoard.  They were
       responsible for versions 1.0 through 1.2.  The color scheme  was  taken
       from Wayne Christopher’s ‘XChess’ program.

       Tim  Mann  was  primarily  responsible  for XBoard versions 1.3 through
       4.2.7, and for WinBoard (a port of XBoard to Microsoft Win32) from  its
       inception through version 4.2.7.

       John  Chanak  contributed the initial implementation of ICS mode.  Evan
       Welsh wrote ‘CMail’, and Patrick Surry helped  in  designing,  testing,
       and  documenting  it.   Elmar  Bartel contributed the new piece bitmaps
       introduced in version 3.2.  Jochen Wiedmann converted the documentation
       to  texinfo.   Frank  McIngvale  added click/click moving, the Analysis
       modes, piece flashing, ZIICS  import,  and  ICS  text  colorization  to
       XBoard.   Hugh  Fisher  added  animated  piece  movement to XBoard, and
       Henrik Gram added  it  to  WinBoard.   Mark  Williams  contributed  the
       initial  (WinBoard-only)  implementation  of many new features added to
       both XBoard  and  WinBoard  in  version  4.1.0,  including  copy/paste,
       premove,   icsAlarm,  autoFlipView,  training  mode,  auto  raise,  and
       blindfold.  Ben Nye contributed X copy/paste code for XBoard.

       In a fork from version 4.2.7, Alessandro Scotti added many elements  to
       the  user interface of WinBoard, including the board textures and font-
       based rendering, the evaluation-graph, move-history  and  engine-output
       window.  He was also responsible for adding the UCI support.

       H. G. Muller continued this fork of the project, producing version 4.3.
       He made WinBoard castling- and e.p.-aware, added variant  support  with
       adjustable  board sizes, the crazyhouse holdings, and the fairy pieces.
       In addition he added most of the adjudication  options,  made  WinBoard
       more  robust  in  dealing with buggy and crashing engines, and extended
       time control with a time-odds and node-count-based modes.  Most of  the
       options  that initially were WinBoard only have now been back-ported to
       XBoard.

       Michel van den Bergh provided the code  for  reading  Polyglot  opening
       books.

       Meanwhile,  some work continued on the GNU XBoard project maintained at
       savannah.gnu.org,  but  version  4.2.8  was  never  released.    Daniel
       Mehrmann was responsible for much of this work.

       Most  recently,  Arun Persaud worked with H. G. Muller to merge all the
       features of the never-released XBoard/WinBoard 4.2.8 of the GNU  XBoard
       project  and the never-released 4.3.16 from H. G.’s fork into a unified
       XBoard/WinBoard  4.4,  which   is   now   available   both   from   the
       savannah.gnu.org web site and the WinBoard forum.

CMAIL

       The  ‘cmail’ program can help you play chess by email with opponents of
       your choice using XBoard as an interface.

       You will usually run ‘cmail’ without giving any options.

   CMail options
       -h     Displays ‘cmail’ usage information.

       -c     Shows the conditions of the GNU  General  Public  License.   See
              Copying.

       -w     Shows  the  warranty  notice  of the GNU General Public License.
              See Copying.

       -v
       -xv    Provides or inhibits verbose output  from  ‘cmail’  and  XBoard,
              useful  for  debugging.  The  ‘-xv’ form also inhibits the cmail
              introduction message.

       -mail
       -xmail Invokes or inhibits the sending of a mail message containing the
              move.

       -xboard
       -xxboard
              Invokes or inhibits the running of XBoard on the game file.

       -reuse
       -xreuse
              Invokes  or  inhibits the reuse of an existing XBoard to display
              the current game.

       -remail
              Resends the last mail  message  for  that  game.  This  inhibits
              running XBoard.

       -game <name>
              The name of the game to be processed.

       -wgames <number>
       -bgames <number>
       -games <number>
              Number of games to start as White, as Black or in total. Default
              is 1 as white and none as black. If only one color is  specified
              then  none  of  the  other  color  is  assumed.  If  no color is
              specified then equal  numbers  of  White  and  Black  games  are
              started,  with the extra game being as White if an odd number of
              total games is specified.

       -me <short name>
       -opp <short name>
              A one-word alias for yourself or your opponent.

       -wname <full name>
       -bname <full name>
       -name <full name>
       -oppname <full name>
              The full name of White, Black, yourself or your opponent.

       -wna <net address>
       -bna <net address>
       -na <net address>
       -oppna <net address>
              The email address of White, Black, yourself or your opponent.

       -dir <directory>
              The directory in which ‘cmail’ keeps its files. This defaults to
              the   environment   variable   ‘$CMAIL_DIR’   or  failing  that,
              ‘$CHESSDIR’, ‘$HOME/Chess’ or ‘~/Chess’. It will be  created  if
              it does not exist.

       -arcdir <directory>
              The   directory  in  which  ‘cmail’  archives  completed  games.
              Defaults to the environment variable ‘$CMAIL_ARCDIR’ or, in  its
              absence,  the  same  directory  as cmail keeps its working files
              (above).

       -mailprog <mail program>
              The program used by cmail to send email messages. This  defaults
              to  the  environment  variable ‘$CMAIL_MAILPROG’ or failing that
              ‘/usr/ucb/Mail’, ‘/usr/ucb/mail’ or ‘Mail’. You will need to set
              this variable if none of the above paths fit your system.

       -logFile <file>
              A  file  in  which  to  dump verbose debugging messages that are
              invoked with the ‘-v’ option.

       -event <event>
              The PGN Event tag (default ‘Email correspondence game’).

       -site <site>
              The PGN Site tag (default ‘NET’).

       -round <round>
              The PGN Round tag (default ‘-’, not applicable).

       -mode <mode>
              The PGN Mode tag (default ‘EM’, Electronic Mail).

       Other options
              Any option flags not listed above are passed through to  XBoard.
              Invoking  XBoard through CMail changes the default values of two
              XBoard options:  The  default  value  for  ‘-noChessProgram’  is
              changed to true; that is, by default no chess engine is started.
              The default value for ‘-timeDelay’ is changed to 0; that is,  by
              default XBoard immediately goes to the end of the game as played
              so far, rather than stepping through the moves one by one.   You
              can  still  set  these  options to whatever values you prefer by
              supplying them on CMail’s command line.  See Options.

   Starting a CMail Game
       Type ‘cmail’ from a shell to start a game as white.  After  an  opening
       message,  you will be prompted for a game name, which is optional -- if
       you simply press <Enter>, the game name will  take  the  form  ‘you-VS-
       opponent’.  You  will  next  be  prompted  for  the  short name of your
       opponent. If you haven’t played this person before, you  will  also  be
       prompted  for his/her email address. ‘cmail’ will then invoke XBoard in
       the background. Make your first move and select ‘Mail  Move’  from  the
       ‘File’ menu. See File Menu. If all is well, ‘cmail’ will mail a copy of
       the move to your opponent. If you select ‘Exit’ without having selected
       ‘Mail Move’ then no move will be made.

   Answering a Move
       When you receive a message from an opponent containing a move in one of
       your games, simply pipe the message through ‘cmail’.  In  some  mailers
       this  is  as simple as typing ‘| cmail’ when viewing the message, while
       in others you may have to save the message to a file and  do  ‘cmail  <
       file’ at the command line. In either case ‘cmail’ will display the game
       using XBoard. If you didn’t exit XBoard when you made your  first  move
       then  ‘cmail’  will  do  its best to use the existing XBoard instead of
       starting a new one. As before, simply make  a  move  and  select  ‘Mail
       Move’  from the ‘File’ menu. See File Menu. ‘cmail’ will try to use the
       XBoard that was most recently used to display the  current  game.  This
       means  that many games can be in progress simultaneously, each with its
       own active XBoard.

       If you want to look at the history or explore a  variation,  go  ahead,
       but  you  must  return to the current position before XBoard will allow
       you to mail a move. If you edit the  game’s  history  you  must  select
       ‘Reload  Same  Game’  from  the ‘File’ menu to get back to the original
       position, then make the move you  want  and  select  ‘Mail  Move’.   As
       before,  if you decide you aren’t ready to make a move just yet you can
       either select ‘Exit’ without  sending  a  move  or  just  leave  XBoard
       running until you are ready.

   Multi-Game Messages
       It  is  possible  to  have  a ‘cmail’ message carry more than one game.
       This feature was implemented to handle IECG (International Email  Chess
       Group)  matches, where a match consists of one game as white and one as
       black, with moves transmitted simultaneously. In case  there  are  more
       general  uses,  ‘cmail’  itself  places  no  limit  on  the  number  of
       black/white games contained in a message; however, XBoard does.

   Completing a Game
       Because XBoard can detect checkmate and stalemate, ‘cmail’ handles game
       termination  sensibly. As well as resignation, the ‘Action’ menu allows
       draws to be offered and accepted for ‘cmail’ games.

       For multi-game messages, only unfinished and just-finished  games  will
       be  included  in  email messages. When all the games are finished, they
       are archived in the user’s archive  directory,  and  similarly  in  the
       opponent’s  when he or she pipes the final message through ‘cmail’. The
       archive file name includes the date the game was started.

   Known CMail Problems
       It’s possible that a strange conjunction of conditions may occasionally
       mean  that ‘cmail’ has trouble reactivating an existing XBoard. If this
       should happen, simply trying it again should work.  If not, remove  the
       file  that  stores  the  XBoard’s PID (‘game.pid’) or use the ‘-xreuse’
       option to force ‘cmail’ to start a new XBoard.

       Versions of ‘cmail’ after 2.16 no longer understand the old file format
       that XBoard used to use and so cannot be used to correspond with anyone
       using an older version.

       Versions of ‘cmail’ older than 2.11 do not handle multi-game  messages,
       so  multi-game  correspondence  is not possible with opponents using an
       older version.

OTHER PROGRAMS YOU CAN USE WITH XBOARD

       Here are some other programs you can use with XBoard

   GNU Chess
       The GNU Chess engine is available from:

       ftp://ftp.gnu.org/gnu/gnuchess/

       You can use XBoard to play a game against GNU Chess,  or  to  interface
       GNU Chess to an ICS.

   Fairy-Max
       Fairy-Max  is a derivative from the once World’s smallest Chess program
       micro-Max, which measures only about 100 lines  of  source  code.   The
       main  difference  with  micro-Max  is  that  Fairy-Max  loads its move-
       generator tables from a file, so that the rules for piece movement  can
       be  easily  configured  to  implement unorthodox pieces.  Fairy-Max can
       therefore play a large number of variants, normal Chess  being  one  of
       those.   In  addition it plays Knightmate, Capablanca and Gothic Chess,
       Shatranj, Courier Chess, Cylinder chess, Berolina Chess, while the user
       can easily define new variants.  It can be obtained from:

       http://home.hccnet.nl/h.g.muller/dwnldpage.html

   HoiChess
       HoiChess  is  a  not-so-very-strong  Chess  engine,  which comes with a
       derivative HoiXiangqi, able to play Chinese Chess. It can  be  obtained
       from the standard Linux repositories through:

       sudo apt-get install hoichess

   Crafty
       Crafty  is  a chess engine written by Bob Hyatt.  You can use XBoard to
       play a game against Crafty, hook Crafty up to an ICS, or use Crafty  to
       interactively analyze games and positions for you.

       Crafty  is a strong, rapidly evolving chess program. This rapid pace of
       development is good, because it means Crafty is always getting  better.
       This  can  sometimes  cause  problems with backwards compatibility, but
       usually the latest version of Crafty will work  well  with  the  latest
       version  of XBoard.  Crafty can be obtained from its author’s FTP site:
       ftp://ftp.cis.uab.edu/hyatt/.

       To use Crafty with XBoard, give the -fcp and -fd  options  as  follows,
       where  <crafty’s  directory>  is  the  directory in which you installed
       Crafty and placed its book and other support files.

   zic2xpm
       The ‘‘zic2xpm’’ program is used to import chess sets from the  ZIICS(*)
       program  into  XBoard.  ‘‘zic2xpm’’ is part of the XBoard distribution.
       ZIICS is available from:

       ftp://ftp.freechess.org/pub/chess/DOS/ziics131.exe

       To import ZIICS pieces, do this:

       1. Unzip ziics131.exe into a directory:

                  unzip -L ziics131.exe -d ~/ziics

       2. Use zic2xpm to convert a set of pieces to XBoard format.

              For example, let’s say you want to use  the  FRITZ4  set.  These
              files are named ‘‘fritz4.*’’ in the ZIICS distribution.

                  mkdir ~/fritz4
                  cd ~/fritz4
                  zic2xpm ~/ziics/fritz4.*

       3. Give XBoard the ‘‘-pixmap’’ option when starting up, e.g.:

                  xboard -pixmap ~/fritz4

              Alternatively, you can add this line to your ‘.Xresources’ file:

                  xboard*pixmapDirectory: ~/fritz4

       (*) ZIICS is a  separate  copyrighted  work  of  Andy  McFarland.   The
       ‘‘ZIICS  pieces’’  are  copyrighted works of their respective creators.
       Files produced by ‘‘zic2xpm’’ are for PERSONAL USE ONLY and may NOT  be
       redistributed  without explicit permission from the original creator(s)
       of the pieces.

COPYRIGHT

       Copyright   (C)   1991   Digital   Equipment   Corporation,    Maynard,
       Massachusetts.

       All Rights Reserved.

       Permission  to  use, copy, modify, and distribute this software and its
       documentation for any  purpose  and  without  fee  is  hereby  granted,
       provided  that the above copyright notice appear in all copies and that
       both that  copyright  notice  and  this  permission  notice  appear  in
       supporting  documentation,  and that the name of Digital not be used in
       advertising or publicity pertaining to  distribution  of  the  software
       without specific, written prior permission.

       Digital   disclaims  all  warranties  with  regard  to  this  software,
       including all implied warranties of merchantability and fitness.  In no
       event   shall   Digital   be   liable  for  any  special,  indirect  or
       consequential damages or any damages whatsoever resulting from loss  of
       use,  data  or profits, whether in an action of contract, negligence or
       other tortious action, arising out of or in connection with the use  or
       performance of this software.

       Enhancements  copyright  (C)  1992-2003,  2004, 2005, 2006, 2007, 2008,
       2009 Free Software Foundation, Inc.

       Published by the Free Software Foundation
       59 Temple Place - Suite 330
       Boston, MA 02111-1307 USA

       Permission is granted to make and distribute verbatim  copies  of  this
       manual  provided  the  copyright  notice and this permission notice are
       preserved on all copies.

       Permission is granted to copy and distribute modified versions of  this
       manual  under  the  conditions for verbatim copying, provided also that
       the section  entitled  ‘‘GNU  General  Public  License,’’  is  included
       exactly  as  in  the  original,  and provided that the entire resulting
       derived work is distributed under the  terms  of  a  permission  notice
       identical to this one.

       Permission  is  granted  to  copy  and  distribute translations of this
       manual into another language, under the above conditions  for  modified
       versions,  except  that  the  section  entitled  ‘‘GNU  General  Public
       License,’’ and this permission notice, may be included in  translations
       approved  by  the  Free  Software Foundation instead of in the original
       English.

GNU GENERAL PUBLIC LICENSE

       Copyright (C) 2007 Free Software Foundation, Inc. ‘http://fsf.org/’

       Everyone is permitted to copy and distribute verbatim copies of this
       license document, but changing it is not allowed.

       The GNU General Public License is a free, copyleft license for software
       and other kinds of works.

       The  licenses  for most software and other practical works are designed
       to take away your freedom to share and change the works.  By  contrast,
       the GNU General Public License is intended to guarantee your freedom to
       share and change all versions of a program -- to make sure  it  remains
       free software for all its users.  We, the Free Software Foundation, use
       the GNU General Public License for most of  our  software;  it  applies
       also to any other work released this way by its authors.  You can apply
       it to your programs, too.

       When we speak of free software, we are referring to freedom, not price.
       Our General Public Licenses are designed to make sure that you have the
       freedom to distribute copies of free software (and charge for  them  if
       you  wish),  that you receive source code or can get it if you want it,
       that you can change the software or  use  pieces  of  it  in  new  free
       programs, and that you know you can do these things.

       To  protect  your  rights,  we  need to prevent others from denying you
       these rights or asking you to surrender  the  rights.   Therefore,  you
       have certain responsibilities if you distribute copies of the software,
       or if you modify it: responsibilities to respect the freedom of others.

       For example, if you distribute copies of such a program, whether gratis
       or for a fee, you must pass on to the recipients the same freedoms that
       you  received.   You  must make sure that they, too, receive or can get
       the source code.  And you must show them these terms so they know their
       rights.

       Developers that use the GNU GPL protect your rights with two steps: (1)
       assert copyright on the software, and (2) offer you this License giving
       you legal permission to copy, distribute and/or modify it.

       For  the  developers’ and authors’ protection, the GPL clearly explains
       that there is no warranty for this free software.  For both users’  and
       authors’  sake,  the  GPL  requires that modified versions be marked as
       changed, so that their problems will not be attributed  erroneously  to
       authors of previous versions.

       Some  devices  are  designed  to  deny  users  access to install or run
       modified  versions  of  the  software   inside   them,   although   the
       manufacturer  can  do  so.  This is fundamentally incompatible with the
       aim  of  protecting  users’  freedom  to  change  the  software.    The
       systematic  pattern  of  such  abuse occurs in the area of products for
       individuals to use, which is precisely where it is  most  unacceptable.
       Therefore,  we  have  designed  this version of the GPL to prohibit the
       practice for those products.  If such problems arise  substantially  in
       other domains, we stand ready to extend this provision to those domains
       in future versions of the GPL, as needed  to  protect  the  freedom  of
       users.

       Finally,  every  program  is threatened constantly by software patents.
       States should not allow patents to  restrict  development  and  use  of
       software on general-purpose computers, but in those that do, we wish to
       avoid the special danger that patents applied to a free  program  could
       make it effectively proprietary.  To prevent this, the GPL assures that
       patents cannot be used to render the program non-free.

       The  precise  terms  and  conditions  for  copying,  distribution   and
       modification follow.

       Definitions.
              ‘‘This  License’’  refers to version 3 of the GNU General Public
              License.

              ‘‘Copyright’’ also means copyright-like laws that apply to other
              kinds of works, such as semiconductor masks.

              ‘‘The  Program’’ refers to any copyrightable work licensed under
              this  License.   Each  licensee   is   addressed   as   ‘‘you’’.
              ‘‘Licensees’’   and   ‘‘recipients’’   may   be  individuals  or
              organizations.

              To ‘‘modify’’ a work means to copy from or adapt all or part  of
              the work in a fashion requiring copyright permission, other than
              the making of an exact copy.  The resulting  work  is  called  a
              ‘‘modified  version’’ of the earlier work or a work ‘‘based on’’
              the earlier work.

              A ‘‘covered work’’ means either the unmodified Program or a work
              based on the Program.

              To  ‘‘propagate’’  a  work  means  to  do anything with it that,
              without permission,  would  make  you  directly  or  secondarily
              liable  for  infringement under applicable copyright law, except
              executing  it  on  a  computer  or  modifying  a  private  copy.
              Propagation  includes  copying,  distribution  (with  or without
              modification), making available  to  the  public,  and  in  some
              countries other activities as well.

              To  ‘‘convey’’ a work means any kind of propagation that enables
              other parties to make or receive copies.  Mere interaction  with
              a  user  through a computer network, with no transfer of a copy,
              is not conveying.

              An  interactive  user  interface  displays  ‘‘Appropriate  Legal
              Notices’’  to  the  extent  that  it  includes  a convenient and
              prominently visible feature that  (1)  displays  an  appropriate
              copyright  notice,  and  (2)  tells  the  user  that there is no
              warranty for the work (except to the extent that warranties  are
              provided),  that  licensees  may  convey  the  work  under  this
              License, and how to  view  a  copy  of  this  License.   If  the
              interface presents a list of user commands or options, such as a
              menu, a prominent item in the list meets this criterion.

       Source Code.
              The ‘‘source code’’ for a work means the preferred form  of  the
              work  for making modifications to it.  ‘‘Object code’’ means any
              non-source form of a work.

              A ‘‘Standard Interface’’ means an interface that  either  is  an
              official standard defined by a recognized standards body, or, in
              the case of interfaces specified for  a  particular  programming
              language,  one  that  is widely used among developers working in
              that language.

              The ‘‘System Libraries’’ of an executable work include anything,
              other  than  the  work  as  a whole, that (a) is included in the
              normal form of packaging a Major Component,  but  which  is  not
              part  of that Major Component, and (b) serves only to enable use
              of the work  with  that  Major  Component,  or  to  implement  a
              Standard  Interface  for which an implementation is available to
              the public in source code form.  A ‘‘Major Component’’, in  this
              context,  means  a  major  essential  component  (kernel, window
              system, and so on) of the specific operating system (if any)  on
              which  the  executable  work runs, or a compiler used to produce
              the work, or an object code interpreter used to run it.

              The ‘‘Corresponding Source’’ for a  work  in  object  code  form
              means  all the source code needed to generate, install, and (for
              an executable work) run the object code and to modify the  work,
              including scripts to control those activities.  However, it does
              not include the  work’s  System  Libraries,  or  general-purpose
              tools  or  generally  available  free  programs  which  are used
              unmodified in performing those activities but which are not part
              of   the  work.   For  example,  Corresponding  Source  includes
              interface definition files associated with source files for  the
              work,  and  the source code for shared libraries and dynamically
              linked subprograms that the work  is  specifically  designed  to
              require,  such as by intimate data communication or control flow
              between those subprograms and other parts of the work.

              The Corresponding Source need not include  anything  that  users
              can   regenerate   automatically   from   other   parts  of  the
              Corresponding Source.

              The Corresponding Source for a work in source code form is  that
              same work.

       Basic Permissions.
              All  rights  granted under this License are granted for the term
              of copyright on the Program, and are  irrevocable  provided  the
              stated conditions are met.  This License explicitly affirms your
              unlimited permission to run the unmodified Program.  The  output
              from  running  a covered work is covered by this License only if
              the output, given its content, constitutes a covered work.  This
              License   acknowledges   your   rights  of  fair  use  or  other
              equivalent, as provided by copyright law.

              You may make, run and propagate covered works that  you  do  not
              convey,  without  conditions  so  long as your license otherwise
              remains in force.  You may convey covered works  to  others  for
              the  sole  purpose of having them make modifications exclusively
              for you, or provide you with facilities for running those works,
              provided  that  you  comply  with  the  terms of this License in
              conveying all material for which you do not  control  copyright.
              Those  thus  making or running the covered works for you must do
              so exclusively on your behalf, under your direction and control,
              on  terms  that  prohibit  them  from  making any copies of your
              copyrighted material outside their relationship with you.

              Conveying under any  other  circumstances  is  permitted  solely
              under the conditions stated below.  Sublicensing is not allowed;
              section 10 makes it unnecessary.

       Protecting UsersLegal Rights From Anti-Circumvention Law.
              No  covered  work  shall  be  deemed  part   of   an   effective
              technological   measure  under  any  applicable  law  fulfilling
              obligations under  article  11  of  the  WIPO  copyright  treaty
              adopted  on  20  December  1996,  or similar laws prohibiting or
              restricting circumvention of such measures.

              When you convey a covered work, you waive  any  legal  power  to
              forbid  circumvention  of  technological  measures to the extent
              such circumvention is effected by exercising rights  under  this
              License  with  respect to the covered work, and you disclaim any
              intention to limit operation or modification of the  work  as  a
              means  of  enforcing,  against  the  work’s users, your or third
              parties’ legal rights to forbid circumvention  of  technological
              measures.

       Conveying Verbatim Copies.
              You  may  convey verbatim copies of the Program’s source code as
              you receive it, in any medium, provided that  you  conspicuously
              and  appropriately publish on each copy an appropriate copyright
              notice; keep intact all notices stating that  this  License  and
              any non-permissive terms added in accord with section 7 apply to
              the code;  keep  intact  all  notices  of  the  absence  of  any
              warranty;  and  give all recipients a copy of this License along
              with the Program.

              You may charge any price or no price  for  each  copy  that  you
              convey,  and  you may offer support or warranty protection for a
              fee.

       Conveying Modified Source Versions.
              You may convey a work based on the Program, or the modifications
              to produce it from the Program, in the form of source code under
              the terms of section 4, provided that you also meet all of these
              conditions:

              The  work must carry prominent notices stating that you modified
              it, and giving a relevant date.

              The work  must  carry  prominent  notices  stating  that  it  is
              released  under  this  License  and  any  conditions added under
              section 7.  This requirement modifies the requirement in section
              4 to ‘‘keep intact all notices’’.

              You must license the entire work, as a whole, under this License
              to anyone who comes into possession of  a  copy.   This  License
              will  therefore  apply,  along  with  any  applicable  section 7
              additional terms, to the whole of the work, and all  its  parts,
              regardless  of  how  they  are  packaged.  This License gives no
              permission to license the work in any other way, but it does not
              invalidate such permission if you have separately received it.

              If  the  work has interactive user interfaces, each must display
              Appropriate  Legal  Notices;  however,  if   the   Program   has
              interactive  interfaces  that  do  not display Appropriate Legal
              Notices, your work need not make them do so.

              A  compilation  of  a  covered  work  with  other  separate  and
              independent  works,  which are not by their nature extensions of
              the covered work, and which are not combined with it such as  to
              form  a  larger  program,  in  or  on  a  volume of a storage or
              distribution  medium,  is  called  an   ‘‘aggregate’’   if   the
              compilation  and  its  resulting copyright are not used to limit
              the access or legal rights of  the  compilation’s  users  beyond
              what  the  individual works permit.  Inclusion of a covered work
              in an aggregate does not cause this  License  to  apply  to  the
              other parts of the aggregate.

       Conveying Non-Source Forms.
              You  may  convey  a  covered  work in object code form under the
              terms of sections 4 and 5, provided that  you  also  convey  the
              machine-readable  Corresponding  Source  under the terms of this
              License, in one of these ways:

              Convey the object code in, or embodied in,  a  physical  product
              (including  a  physical distribution medium), accompanied by the
              Corresponding  Source  fixed  on  a  durable   physical   medium
              customarily used for software interchange.

              Convey  the  object  code in, or embodied in, a physical product
              (including a physical distribution  medium),  accompanied  by  a
              written  offer,  valid for at least three years and valid for as
              long as you offer spare  parts  or  customer  support  for  that
              product  model,  to  give  anyone  who possesses the object code
              either (1) a copy  of  the  Corresponding  Source  for  all  the
              software  in  the  product that is covered by this License, on a
              durable  physical   medium   customarily   used   for   software
              interchange,  for  a  price no more than your reasonable cost of
              physically performing this conveying of source, or (2) access to
              copy  the  Corresponding  Source  from  a  network  server at no
              charge.

              Convey individual copies of the object code with a copy  of  the
              written   offer  to  provide  the  Corresponding  Source.   This
              alternative is allowed only  occasionally  and  noncommercially,
              and  only if you received the object code with such an offer, in
              accord with subsection 6b.

              Convey the object code by  offering  access  from  a  designated
              place  (gratis  or for a charge), and offer equivalent access to
              the Corresponding Source in the same way through the same  place
              at  no  further charge.  You need not require recipients to copy
              the Corresponding Source along with the  object  code.   If  the
              place  to  copy  the  object  code  is  a  network  server,  the
              Corresponding Source may be on a different server  (operated  by
              you   or   a  third  party)  that  supports  equivalent  copying
              facilities, provided you maintain clear directions next  to  the
              object  code  saying  where  to  find  the Corresponding Source.
              Regardless of what server hosts the  Corresponding  Source,  you
              remain  obligated  to ensure that it is available for as long as
              needed to satisfy these requirements.

              Convey the object code using peer-to-peer transmission, provided
              you  inform  other peers where the object code and Corresponding
              Source of the work are being offered to the general public at no
              charge under subsection 6d.

              A  separable  portion  of  the object code, whose source code is
              excluded from the Corresponding Source as a System Library, need
              not be included in conveying the object code work.

              A  ‘‘User  Product’’ is either (1) a ‘‘consumer product’’, which
              means any tangible personal property which is normally used  for
              personal,   family,  or  household  purposes,  or  (2)  anything
              designed  or  sold  for  incorporation  into  a  dwelling.    In
              determining  whether  a  product is a consumer product, doubtful
              cases shall be resolved in favor of coverage.  For a  particular
              product  received by a particular user, ‘‘normally used’’ refers
              to a typical or common use of that class of product,  regardless
              of  the status of the particular user or of the way in which the
              particular user actually uses, or expects or is expected to use,
              the  product.   A  product  is  a consumer product regardless of
              whether the product has substantial  commercial,  industrial  or
              non-consumer   uses,   unless   such  uses  represent  the  only
              significant mode of use of the product.

              ‘‘Installation  Information’’  for  a  User  Product  means  any
              methods,  procedures,  authorization  keys, or other information
              required to install and execute modified versions of  a  covered
              work  in  that  User  Product  from  a  modified  version of its
              Corresponding Source.  The information must  suffice  to  ensure
              that the continued functioning of the modified object code is in
              no case prevented or interfered with solely because modification
              has been made.

              If  you  convey  an  object  code work under this section in, or
              with, or specifically for  use  in,  a  User  Product,  and  the
              conveying  occurs as part of a transaction in which the right of
              possession and use of the User Product  is  transferred  to  the
              recipient  in  perpetuity or for a fixed term (regardless of how
              the transaction  is  characterized),  the  Corresponding  Source
              conveyed   under   this  section  must  be  accompanied  by  the
              Installation Information.  But this requirement does  not  apply
              if  neither  you  nor  any  third  party  retains the ability to
              install modified object code on the User Product  (for  example,
              the work has been installed in ROM).

              The  requirement  to  provide  Installation Information does not
              include a requirement to continue to  provide  support  service,
              warranty,  or  updates  for  a  work  that  has been modified or
              installed by the recipient, or for the User Product in which  it
              has  been  modified  or  installed.   Access to a network may be
              denied when the modification  itself  materially  and  adversely
              affects  the  operation of the network or violates the rules and
              protocols for communication across the network.

              Corresponding  Source  conveyed,  and  Installation  Information
              provided,  in  accord with this section must be in a format that
              is publicly documented (and with an implementation available  to
              the  public  in  source  code form), and must require no special
              password or key for unpacking, reading or copying.

       Additional Terms.
              ‘‘Additional permissions’’ are terms that supplement  the  terms
              of  this  License  by  making exceptions from one or more of its
              conditions.  Additional permissions that are applicable  to  the
              entire  Program shall be treated as though they were included in
              this License, to the extent that they are valid under applicable
              law.   If  additional  permissions  apply  only  to  part of the
              Program,  that  part  may  be  used   separately   under   those
              permissions,  but  the  entire  Program remains governed by this
              License without regard to the additional permissions.

              When you convey a copy of a covered work, you may at your option
              remove  any  additional  permissions from that copy, or from any
              part of it.  (Additional permissions may be written  to  require
              their  own  removal  in certain cases when you modify the work.)
              You may place additional permissions on material, added  by  you
              to  a  covered  work, for which you have or can give appropriate
              copyright permission.

              Notwithstanding  any  other  provision  of  this  License,   for
              material  you  add  to a covered work, you may (if authorized by
              the copyright holders of that material) supplement the terms  of
              this License with terms:

              Disclaiming  warranty or limiting liability differently from the
              terms of sections 15 and 16 of this License; or

              Requiring preservation of specified reasonable legal notices  or
              author attributions in that material or in the Appropriate Legal
              Notices displayed by works containing it; or

              Prohibiting misrepresentation of the origin of that material, or
              requiring  that  modified versions of such material be marked in
              reasonable ways as different from the original version; or

              Limiting the use for publicity purposes of names of licensors or
              authors of the material; or

              Declining  to  grant  rights under trademark law for use of some
              trade names, trademarks, or service marks; or

              Requiring indemnification  of  licensors  and  authors  of  that
              material  by  anyone  who  conveys  the  material  (or  modified
              versions of it) with contractual assumptions of liability to the
              recipient,  for any liability that these contractual assumptions
              directly impose on those licensors and authors.

              All  other  non-permissive  additional  terms   are   considered
              ‘‘further  restrictions’’  within the meaning of section 10.  If
              the Program as you received it, or any part of  it,  contains  a
              notice  stating that it is governed by this License along with a
              term that is a further restriction, you may  remove  that  term.
              If a license document contains a further restriction but permits
              relicensing or conveying under this License, you may  add  to  a
              covered  work  material  governed  by  the terms of that license
              document, provided that the further restriction does not survive
              such relicensing or conveying.

              If  you add terms to a covered work in accord with this section,
              you must place, in the relevant source files, a statement of the
              additional  terms  that  apply  to  those  files,  or  a  notice
              indicating where to find the applicable terms.

              Additional terms, permissive or non-permissive, may be stated in
              the   form  of  a  separately  written  license,  or  stated  as
              exceptions; the above requirements apply either way.

       Termination.
              You may not  propagate  or  modify  a  covered  work  except  as
              expressly provided under this License.  Any attempt otherwise to
              propagate or modify it is void, and will automatically terminate
              your  rights  under  this License (including any patent licenses
              granted under the third paragraph of section 11).

              However, if you cease all violation of this License,  then  your
              license  from  a  particular  copyright holder is reinstated (a)
              provisionally, unless and until the copyright holder  explicitly
              and finally terminates your license, and (b) permanently, if the
              copyright holder fails to notify you of the  violation  by  some
              reasonable means prior to 60 days after the cessation.

              Moreover,  your  license  from  a particular copyright holder is
              reinstated permanently if the copyright holder notifies  you  of
              the  violation  by some reasonable means, this is the first time
              you have received notice of violation of this License  (for  any
              work)  from  that  copyright  holder, and you cure the violation
              prior to 30 days after your receipt of the notice.

              Termination of your rights under this section does not terminate
              the  licenses of parties who have received copies or rights from
              you under this License.  If your rights have been terminated and
              not  permanently  reinstated,  you do not qualify to receive new
              licenses for the same material under section 10.

       Acceptance Not Required for Having Copies.
              You are not required to accept this License in order to  receive
              or  run  a  copy  of  the  Program.   Ancillary propagation of a
              covered work occurring solely as a consequence of using peer-to-
              peer  transmission  to  receive a copy likewise does not require
              acceptance.  However, nothing other than this License grants you
              permission  to  propagate  or  modify  any  covered work.  These
              actions infringe copyright if you do not  accept  this  License.
              Therefore,  by  modifying  or  propagating  a  covered work, you
              indicate your acceptance of this License to do so.

       Automatic Licensing of Downstream Recipients.
              Each time you convey a covered work, the recipient automatically
              receives  a  license from the original licensors, to run, modify
              and propagate that work, subject to this License.  You  are  not
              responsible  for enforcing compliance by third parties with this
              License.

              An ‘‘entity transaction’’ is a transaction transferring  control
              of  an  organization,  or  substantially  all  assets of one, or
              subdividing  an  organization,  or  merging  organizations.   If
              propagation   of   a   covered   work  results  from  an  entity
              transaction, each party to that transaction who receives a  copy
              of  the  work  also  receives  whatever licenses to the work the
              party’s predecessor in interest had  or  could  give  under  the
              previous   paragraph,   plus   a  right  to  possession  of  the
              Corresponding  Source  of  the  work  from  the  predecessor  in
              interest,  if  the  predecessor  has  it  or  can  get  it  with
              reasonable efforts.

              You may not impose any further restrictions on the  exercise  of
              the rights granted or affirmed under this License.  For example,
              you may not impose a license fee, royalty, or other  charge  for
              exercise  of  rights granted under this License, and you may not
              initiate litigation (including a cross-claim or counterclaim  in
              a  lawsuit)  alleging  that  any  patent  claim  is infringed by
              making, using, selling, offering  for  sale,  or  importing  the
              Program or any portion of it.

       Patents.
              A ‘‘contributor’’ is a copyright holder who authorizes use under
              this License of the Program or a work on which  the  Program  is
              based.   The  work  thus  licensed  is  called the contributor’s
              ‘‘contributor version’’.

              A contributor’s  ‘‘essential  patent  claims’’  are  all  patent
              claims  owned  or controlled by the contributor, whether already
              acquired or hereafter acquired, that would be infringed by  some
              manner,  permitted by this License, of making, using, or selling
              its contributor version, but do not include claims that would be
              infringed  only  as a consequence of further modification of the
              contributor  version.   For   purposes   of   this   definition,
              ‘‘control’’  includes the right to grant patent sublicenses in a
              manner consistent with the requirements of this License.

              Each contributor grants you a non-exclusive, worldwide, royalty-
              free  patent  license  under  the contributor’s essential patent
              claims, to make, use, sell, offer for sale, import and otherwise
              run,  modify  and  propagate  the  contents  of  its contributor
              version.

              In the following three paragraphs, a ‘‘patent license’’  is  any
              express  agreement  or  commitment,  however denominated, not to
              enforce a patent (such as an express permission  to  practice  a
              patent  or  covenant  not  to  sue for patent infringement).  To
              ‘‘grant’’ such a patent license to a party means to make such an
              agreement  or  commitment  not  to  enforce a patent against the
              party.

              If you convey a covered work,  knowingly  relying  on  a  patent
              license,  and  the  Corresponding  Source  of  the  work  is not
              available for anyone to copy, free of charge and under the terms
              of  this License, through a publicly available network server or
              other readily accessible means, then you must either  (1)  cause
              the  Corresponding  Source to be so available, or (2) arrange to
              deprive yourself of the benefit of the patent license  for  this
              particular work, or (3) arrange, in a manner consistent with the
              requirements of this License, to extend the  patent  license  to
              downstream  recipients.   ‘‘Knowingly  relying’’  means you have
              actual  knowledge  that,  but  for  the  patent  license,   your
              conveying the covered work in a country, or your recipient’s use
              of the covered work in a country, would  infringe  one  or  more
              identifiable  patents  in  that  country that you have reason to
              believe are valid.

              If, pursuant to or in connection with a  single  transaction  or
              arrangement,  you  convey,  or propagate by procuring conveyance
              of, a covered work, and grant a patent license to  some  of  the
              parties  receiving  the  covered  work  authorizing them to use,
              propagate, modify or convey a specific copy of the covered work,
              then  the  patent license you grant is automatically extended to
              all recipients of the covered work and works based on it.

              A patent license is ‘‘discriminatory’’ if it  does  not  include
              within  the scope of its coverage, prohibits the exercise of, or
              is conditioned on the non-exercise of one or more of the  rights
              that  are  specifically granted under this License.  You may not
              convey a covered work if you are a party to an arrangement  with
              a  third party that is in the business of distributing software,
              under which you make payment to the third  party  based  on  the
              extent  of  your activity of conveying the work, and under which
              the third party grants, to any of the parties who would  receive
              the  covered  work from you, a discriminatory patent license (a)
              in connection with copies of the covered work  conveyed  by  you
              (or  copies made from those copies), or (b) primarily for and in
              connection with specific products or compilations  that  contain
              the  covered  work, unless you entered into that arrangement, or
              that patent license was granted, prior to 28 March 2007.

              Nothing in this License  shall  be  construed  as  excluding  or
              limiting  any  implied license or other defenses to infringement
              that may otherwise be available to you under  applicable  patent
              law.

       No Surrender of OthersFreedom.
              If  conditions  are  imposed  on  you  (whether  by court order,
              agreement or otherwise) that contradict the conditions  of  this
              License,  they  do  not  excuse  you from the conditions of this
              License.  If you cannot convey a covered work so as  to  satisfy
              simultaneously your obligations under this License and any other
              pertinent obligations, then as a consequence you may not  convey
              it at all.  For example, if you agree to terms that obligate you
              to collect a royalty for further conveying from  those  to  whom
              you  convey  the  Program,  the  only way you could satisfy both
              those terms and this License would be to refrain  entirely  from
              conveying the Program.

       Use with the GNU Affero General Public License.
              Notwithstanding  any  other  provision of this License, you have
              permission to link or combine  any  covered  work  with  a  work
              licensed  under  version  3  of  the  GNU  Affero General Public
              License into a single combined work, and to convey the resulting
              work.   The  terms of this License will continue to apply to the
              part which is the covered work, but the special requirements  of
              the  GNU  Affero  General Public License, section 13, concerning
              interaction through a network will apply to the  combination  as
              such.

       Revised Versions of this License.
              The  Free  Software  Foundation  may  publish revised and/or new
              versions of the GNU General Public License from  time  to  time.
              Such  new  versions  will  be  similar  in spirit to the present
              version, but may differ in detail to  address  new  problems  or
              concerns.

              Each  version  is given a distinguishing version number.  If the
              Program specifies that a certain numbered  version  of  the  GNU
              General  Public  License ‘‘or any later version’’ applies to it,
              you have the option of following the terms and conditions either
              of  that  numbered  version or of any later version published by
              the Free Software Foundation.  If the Program does not specify a
              version number of the GNU General Public License, you may choose
              any version ever published by the Free Software Foundation.

              If the Program specifies that a proxy can  decide  which  future
              versions  of  the  GNU  General Public License can be used, that
              proxy’s public statement of acceptance of a version  permanently
              authorizes you to choose that version for the Program.

              Later  license  versions  may  give  you additional or different
              permissions.  However, no additional obligations are imposed  on
              any  author  or copyright holder as a result of your choosing to
              follow a later version.

       Disclaimer of Warranty.
              THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
              APPLICABLE  LAW.   EXCEPT  WHEN  OTHERWISE STATED IN WRITING THE
              COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM  ‘‘AS
              IS’’  WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED,
              INCLUDING,  BUT  NOT  LIMITED  TO,  THE  IMPLIED  WARRANTIES  OF
              MERCHANTABILITY  AND  FITNESS  FOR  A  PARTICULAR  PURPOSE.  THE
              ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM  IS
              WITH  YOU.   SHOULD  THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE
              COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.

       Limitation of Liability.
              IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR  AGREED  TO  IN
              WRITING  WILL  ANY  COPYRIGHT  HOLDER,  OR  ANY  OTHER PARTY WHO
              MODIFIES AND/OR CONVEYS  THE  PROGRAM  AS  PERMITTED  ABOVE,  BE
              LIABLE  TO  YOU  FOR  DAMAGES,  INCLUDING  ANY GENERAL, SPECIAL,
              INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF  THE  USE  OR
              INABILITY  TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS
              OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
              YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH
              ANY OTHER PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN
              ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

       Interpretation of Sections 15 and 16.
              If  the  disclaimer  of  warranty  and  limitation  of liability
              provided above cannot be given local legal effect  according  to
              their  terms,  reviewing  courts shall apply local law that most
              closely approximates an absolute waiver of all  civil  liability
              in  connection with the Program, unless a warranty or assumption
              of liability accompanies a copy of the Program in return  for  a
              fee.

              If  you  develop  a  new  program,  and you want it to be of the
              greatest possible use to the public, the  best  way  to  achieve
              this is to make it free software which everyone can redistribute
              and change under these terms.

              To do so, attach the following notices to the  program.   It  is
              safest  to  attach them to the start of each source file to most
              effectively state the  exclusion  of  warranty;  and  each  file
              should  have  at  least  the ‘‘copyright’’ line and a pointer to
              where the full notice is found.

              ONE LINE TO GIVE THE PROGRAM’S NAME AND A BRIEF IDEA OF WHAT IT DOES.
              Copyright (C) YEAR NAME OF AUTHOR

              This program is free software: you can redistribute it and/or modify
              it under the terms of the GNU General Public License as published by
              the Free Software Foundation, either version 3 of the License, or (at
              your option) any later version.

              This program is distributed in the hope that it will be useful, but
              WITHOUT ANY WARRANTY; without even the implied warranty of
              MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
              General Public License for more details.

              You should have received a copy of the GNU General Public License
              along with this program.  If not, see ‘http://www.gnu.org/licenses/’.

              Also add information on how to contact  you  by  electronic  and
              paper mail.

              If the program does terminal interaction, make it output a short
              notice like this when it starts in an interactive mode:

              PROGRAM Copyright (C) YEAR NAME OF AUTHOR
              This program comes with ABSOLUTELY NO WARRANTY; for details type ‘show w’.
              This is free software, and you are welcome to redistribute it
              under certain conditions; type ‘show c’ for details.

              The hypothetical commands ‘show w’ and ‘show c’ should show  the
              appropriate  parts  of  the  General Public License.  Of course,
              your program’s commands might be different; for a GUI interface,
              you would use an ‘‘about box’’.

              You  should also get your employer (if you work as a programmer)
              or school, if any, to sign a ‘‘copyright  disclaimer’’  for  the
              program, if necessary.  For more information on this, and how to
              apply      and      follow      the      GNU      GPL,       see
              ‘http://www.gnu.org/licenses/’.

              The  GNU  General  Public  License does not permit incorporating
              your program into proprietary programs.  If your  program  is  a
              subroutine  library,  you  may consider it more useful to permit
              linking proprietary applications with the library.  If  this  is
              what  you  want to do, use the GNU Lesser General Public License
              instead   of   this   License.    But   first,    please    read
              ‘http://www.gnu.org/philosophy/why-not-lgpl.html’.