ditroff

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 Osanna 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  typeset-
       ter.

       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 Osanna’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 function-
       ality 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.
	      Osanna 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 Free Software Foundation, Inc.

       This document is distributed under the terms of the FDL (GNU Free Doc-
       umentation License) version 1.1 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 1.18.1.1	       19 February 2002			   DITROFF(7)