groff
Groff, short for GNU troff, is a free software typesetting system used primarily on Unix-like systems. It reads plain-text input containing formatting commands and produces formatted output in various devices and formats. As part of the GNU project, groff is distributed under the GNU General Public License.
Groff implements the troff/nroff document formatter family. It originated from the troff tool developed at Bell
Macro packages include -man, -mdoc, -me, -mm, -ms, and -mom (modern macros). These provide conventions for formatting
Groff is widely used for producing manual pages and technical documents and remains standard in many GNU/Linux
See also: troff, nroff, roff, man page, mdoc, macro packages.