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 maintenance, hyphenation breaking, and consistent paragraph indentation. Early in its development, the program gained the ability to prepare output for a phototypesetter; a document could then be prepared for output to 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 upon a variety of output formats or devices, including PDF, HTML, laser printers, and terminal displays.

roff input contains 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.