Provided by: groff_1.22.3-7_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 Ossanna 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 Ossanna'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  User's  Manual  by  J.  F.
              Ossanna  and  Brian  Kernighan,  see Bell Labs CSTR #54 ⟨http://

       [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 © 2001-2014 Free Software Foundation, Inc.

       This file is part of groff, the GNU roff type-setting system.

       Permission  is  granted to copy, distribute and/or modify this document
       under the terms of the GNU Free Documentation License, Version  1.3  or
       any  later  version  published by the Free Software Foundation; with no
       Front-Cover Texts, and with no Back-Cover Texts.

       A copy of the Free Documentation License is included as a  file  called
       FDL  in  the  main  directory  of  the groff source package, it is also
       available  on-line  at  the  GNU  copyleft  site   ⟨


       It  was  written  by Bernd Warken ⟨⟩ and is
       maintained by Werner Lemberg ⟨⟩.