DITROFF(7)						 Miscellaneous Information Manual						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  ori-
       ented  tty  output, while the troff program generated graphical output for exactly one output device, the Wang Graphic Systems CAT typeset-
       ter.

       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 han-
       dles 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 <bwarken@mayn.de> and is maintained by Werner
       Lemberg <wl@gnu.org>.

Groff Version 1.21						   25 June 2012 							DITROFF(7)