Provided by: groff_1.18.1.1-16_i386 bug


       ditroff - classical device independent roff


       The  name  ditroff  once  marked  a development level of the troff text
       processing system.  In actual roff(7) systems, the name troff  is  used
       as a synonym for ditroff.

       The  first  roff  system  was  written  by  Joe Osanna around 1973.  It
       supported only two output devices,  the  nroff  program  produced  text
       oriented tty output, while the troff program generated graphical output
       for exactly one output device, the Wang Graphic Systems CAT typesetter.

       In  1979,  Brian  Kernighan  rewrote  troff  to support more devices by
       creating an intermediate output format for troff that can be  fed  into
       postprocessor  programs  which  actually do the printout on the device.
       Kernighan’s version marks what is known as classical troff  today.   In
       order  to distinguish it from Osanna’s original mono-device version, it
       was called ditroff (device independent troff) on some  systems,  though
       this naming isn’t mentioned in the classical documentation.

       Today,  any  existing  roff system is based on Kernighan’s multi-device
       troff.  The distinction between troff and ditroff isn’t  necessary  any
       longer,   for   each   modern   troff  provides  already  the  complete
       functionality of ditroff.  On most systems, the name troff is  used  to
       denote ditroff.

       The  easiest  way  to  use  ditroff is the GNU roff system, groff.  The
       groff(1) program is  a  wrapper  around  (di)troff  that  automatically
       handles postprocessing.


       [CSTR #54]
              The  1992  revision  of  the  Nroff/Troff Users Manual by J. F.
              Osanna and Brian Kernighan, see
              Bell   Labs   CSTR   #54    〈

       [CSTR #97]
              A   Typesetter-independent  TROFF  by  Brian  Kernighan  is  the
              original  documentation  of   the   first   multi-device   troff
              (ditroff), see
              Bell    Labs   CSTR   #97   〈

              This document gives details on the history and concepts of roff.

              The actual implementation of ditroff.

              The  GNU  roff  program and pointers to all documentation around

              The groff version of the intermediate output language, the basis
              for multi-devicing.


       Copyright (C) 2001, 2002 Free Software Foundation, Inc.

       This  document  is  distributed  under  the  terms of the FDL (GNU Free
       Documentation License) version 1.1 or later.  You should have  received
       a  copy  of the FDL on your system, it is also available on-line at the
       GNU copyleft site 〈〉.

       This document is part of groff, the  GNU  roff  distribution.   It  was
       written  by  Bernd Warken 〈〉 and is maintained by Werner
       Lemberg 〈〉.