Texinfo is a documentation system that uses a single source file to produce both online information and printed output. This means that instead of writing several different documents, one for each output format, you need only write one document.
Using Texinfo, you can create a printed document (via the TeX typesetting system) in PDF or PostScript format, including chapters, sections, cross-references, and indices. From the same Texinfo source file, you can create an HTML output file suitable for use with a web browser, you can create an Info file with special features to make browsing documentation easy, and also create a DocBook file or a transliteration to XML format.
A Texinfo source file is a plain text file containing text interspersed with @-commands (words preceded by an ‘@’) that tell the Texinfo processors what to do. Texinfo’s markup commands are almost entirely semantic; that is, they specify the intended meaning of text in the document, rather than physical formatting instructions. You can edit a Texinfo file with any text editor, but it is especially convenient to use GNU Emacs since that editor has a special mode, called Texinfo mode, that provides various Texinfo-related features. (See Using Texinfo Mode.)
Texinfo was devised specifically for the purpose of writing software documentation and manuals. If you want to write a good manual for your program, Texinfo has many features which we hope will make your job easier. However, Texinfo is not intended to be a general-purpose formatting program. It provides almost no commands for controlling the final formatting, so may be inappropriate for your needs if you if you want to lay out a newspaper, devise a glossy magazine ad, or follow the exact formatting requirements of a publishing house.
Spell “Texinfo” with a capital “T” and the other letters in lowercase. The first syllable of “Texinfo” is pronounced like “speck”, not “hex”. This odd pronunciation is derived from the pronunciation of TeX. Pronounce TeX as if the ‘X’ were the last sound in the name ‘Bach’. In the word TeX, the ‘X’ is, rather than the English letter “ex”, actually the Greek letter “chi”.
Texinfo is the official documentation format of the GNU project. More information, including manuals for GNU packages, is available at the GNU documentation web page.