Texinfo is a typesetting syntax used for generating documentation in both on-line and printed form (creating filetypes as dvi, html, pdf, etc., and a specific hypertext format, Info) with a single source file.

Similar to the LaTeX syntax, all the normal features of a book, such as chapters, sections, cross references, tables and indices are available for use in documents.

While Texinfo is used for writing the documentation of GNU software, which typically is used in Unix-like environments such as Linux, where man pages are the traditional format for documentation, the rationale for this is that man pages have a strict conventional format, used traditionally as quick reference guides, whereas typical Texinfo applications are for tutorials as well as reference manuals.

Texinfo enables structuring a document like a book with chapters, sections, cross references and indices.

The Texinfo format was created by Richard M. Stallman, combining another system for print output in use at MIT called BoTeX, with the online Info hyperlinked documentation system, also created by Stallman on top of the TECO implementation of Emacs.