Text (The GNU Troff Manual)

### 5.1 Text

AT&T `troff` was designed to take input as it would be composed on a typewriter, including the teletypewriters used as early computer terminals, and relieve the user drafting a document of concern with details like line length, hyphenation breaking, and the achievement of straight margins. Early in its development, the program gained the ability to prepare output for a phototypesetter; a document could then be prepared for output to either a teletypewriter, a phototypesetter, or both. GNU `troff` continues this tradition of permitting an author to compose a single master version of a document which can then be rendered for a variety of output formats or devices.

`roff` input files contain text interspersed with instructions to control the formatter. Even in the absence of such instructions, GNU `troff` still processes its input in several ways, by filling, hyphenating, breaking, and adjusting it, and supplementing it with inter-sentence space.