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 pro-
       cessing 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 sup-
       ported 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 typesetter.

       In 1979, Brian Kernighan rewrote troff to support more devices by  cre-
       ating  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 functional-
       ity  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	origi-
	      nal 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, 2007-2009, 2012 Free Software Founda-
       tion, Inc.

       This document is distributed under the terms of the FDL (GNU Free Docu-
       mentation  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	<groff-bernd.warken-72@web.de>	and  is	 main-
       tained by Werner Lemberg <wl@gnu.org>.



Groff Version 1.22.2		7 February 2013			    DITROFF(7)