Troff

Troff was a document processing system developed by AT&T for the Unix operating system. It features commands to designate fonts, spacing, paragraphs, margins, footnotes and more. Extensions are available for producing tables, diagrams, and mathmatics. Inputs to troff are plain text files that can be created by any text editor.

These are some variants: nroff? was designed to generate formatted plain text instead of typeset output. groff? is the GNU replacement for troff and nroff, which is Free software.

Use of troff has dwindled in the 1990's, being largely suppanted by other programs such as Interleaf? and Framemaker?, and LaTeX.