1. GNU troff text-formatting system This package contains optional components of the GNU troff text-formatting system. The core package, groff-base, contains the traditional tools like troff, nroff, tbl, eqn, and pic. This package contains additional devices and drivers for output to DVI, HTML, HP LaserJet printers, Canon CAPSL LBP-4 and LBP-8 printers, and PostScript. Besides these, the groff package contains man pages describing the language and its macro sets, info documentation, and a number of supplementary programs: - grn, a preprocessor for pictures in the 'gremlin' format; - tfmtodit, which creates font files for use with 'groff -Tdvi'; - hpftodit, which creates font files for use with 'groff -Tlj4'; - afmtodit, which creates font files for use with 'groff -Tps'; - refer, which preprocesses bibliographic references for use with groff; - indxbib, which creates inverted indices for bibliographic databases used by 'refer'; - lkbib and lookbib, which search bibliographic databases; - addftinfo, which adds metric information to troff font files for use with groff; - pfbtops, which translates a PostScript font in .pfb format to ASCII for use with groff; - mmroff, a simple groff preprocessor which expands references in mm. All the standard macro packages are supported. From Debian 3.0r0 APT

2. Groff is a document formatting system. Groff takes standard text and formatting commands as input and produces formatted output. The created documents can be shown on a display or printed on a printer. Groff's formatting commands allow you to specify font type and size, boldtype, italic type, the number and size of columns on a page, and more. You should install groff if you want to use it as a document formatting system. Groff can also be used to format man pages. If you are going to use groff with the X Window System, you'll also need to install the groff-gxditview package. From Mandrake 9.0 RPM

3. front end for the groff document formatting system From whatis