groff 1.21-6 source package in Ubuntu

 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 (when recommended packages are
 installed - see below), HP LaserJet printers, and Canon CAPSL LBP-4 and
 LBP-8 printers.
 .
 The X75, X75-12, X100, and X100-12 devices, which allow groff output to be
 conveniently viewed on an X display using the standard X11 fonts, are now
 included here. They were previously in a separate package, groff-x11.
 .
 Besides these, the groff package contains man pages describing the language
 and its macro sets, info documentation, and a number of supplementary
 programs:
 .
  - gxditview, which is used to display the output of the X* devices, and
    can also be used to view PostScript output from groff;
  - 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;
  - pic2graph, which converts PIC diagrams into cropped image files;
  - eqn2graph, which converts EQN equations into cropped image files.
 .
 All the standard macro packages are supported.
 .
 Some facilities only work if certain recommended packages are installed:
 .
  - ghostscript, netpbm, psutils: required for HTML output;
  - imagemagick: required for the pic2graph and eqn2graph programs;
  - libpaper1: paper size detection in dvi, lbp, lj4, and ps devices (falls
    back to a4 if not installed).

 This package contains the traditional UN*X text formatting tools
 troff, nroff, tbl, eqn, and pic. These utilities, together with the
 man-db package, are essential for displaying the on-line manual pages.
 .
 groff-base is a stripped-down package containing the necessary components
 to read manual pages in ASCII, Latin-1, and UTF-8, plus the PostScript
 device (groff's default). Users who want a full groff installation, with
 the standard set of devices, fonts, macros, and documentation, should
 install the groff package.