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Basic data

developer James Clark
Publishing year June 1990
Current  version 1.22.4
( December 23, 2018 )
operating system UNIX / Linux
programming language C.
category Pleading
License GPL ( Free Software )

Groff [ dʒiːrɒf ] is the GNU implementation services from dripping , a typesetting system which by AT & T for the operating system Unix was developed. On many Unix and GNU-based systems, groff is used to display instructions for use ( man pages ).


The first version 0.3.1 released in 1990 was largely implemented in C ++ by James Clark within the GNU project . In 1991 the first stable version followed with version 1.04. In 1999 Werner Lemberg and Ted Harding took over the further care. The reimplementation was done to prevent copyright problems with the old, proprietary code. Groff is continuously being developed.

Differences to AT&T-troff

The greatest possible attention was paid to compatibility during development. Differences are groff_diff(7)documented in the man page .

The Ditroff intermediate format was retained, but with some extensions. Among other things, drivers for PostScript , PCL and DVI are available. Also can directly HTML generated.

nroff creates formatted text files and can also embed codes there for the terminal control in order to display font styles such as bold , italic or even colored text on the corresponding terminals . In addition, it can output several character sets .

Since most of the troff commands are extremely primitive, some so-called macro packages are included . So there are z. B. the packages Mom, Me, Mm and Ms for documents, Doc and Man for man pages . These are loaded accordingly when groff is called on the command line.

Web links


  1. FFII News 1999 Week 20 .
  2. cf. GNU troff , Git project archive