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 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.

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.

       [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.

       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.

COPYING

       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.

AUTHORS

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

Groff Version 1.22.3                             28 January 2016                                      DITROFF(7)