DITROFF(7)                                                                                                            DITROFF(7)



NAME
       ditroff - classical device independent roff

DESCRIPTION
       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  sys-
       tems, 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.

SEE ALSO
       [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://cm.bell-labs.com/cm/cs/cstr/54.ps.gz>;.

       [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 <http://cm.bell-labs.com/cm/cs/cstr/97.ps.gz>;.

       roff(7)
              This document gives details on the history and concepts of roff.

       troff(1)
              The actual implementation of ditroff.

       groff(1)
              The GNU roff program and pointers to all documentation around groff.

       groff_out(5)
              The groff version of the intermediate output language, the basis for multi-devicing.

AUTHORS
       Copyright (C) 2001, 2002, 2004, 2007, 2008, 2009 Free Software Foundation, Inc.

       This document is distributed under the terms of the FDL (GNU Free Documentation  License)  version  1.3  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 <http://
       www.gnu.org/copyleft/fdl.html>.

       This document is part of groff, the GNU roff distribution.  It was written by Bernd Warken <bwarkenATmayn.de> and is main-
       tained by Werner Lemberg <wlATgnu.org>.



Groff Version 1.20.1                                     9 January 2009                                               DITROFF(7)