Using Texinfo, you can create a printed document with the normal features of a book, including chapters, sections, cross references, and indices. From the same Texinfo source file, you can create a menu-driven, on-line Info file with nodes, menus, cross references, and indices. You can, if you wish, make the chapters and sections of the printed document correspond to the nodes of the on-line information; and you use the same cross references and indices for both the Info file and the printed work. The GNU Emacs Manual is a good example of a Texinfo file, as is this manual.

To make a printed document, you process a Texinfo source file with the TeX typesetting program. This creates a DVI file that you can typeset and print as a book or report. (Note that the Texinfo language is completely different from TeX's usual language, PlainTeX, which Texinfo replaces.) If you do not have TeX, but do have troff or nroff, you can use the texi2roff program instead.

To make an Info file, you process a Texinfo source file with the makeinfo utility or Emacs's texinfo-format-buffer command; this creates an Info file that you can install on-line.

TeX and texi2roff work with many types of printer; similarly, Info works with almost every type of computer terminal. This power makes Texinfo a general purpose system, but brings with it a constraint, which is that a Texinfo file may contain only the customary "typewriter" characters (letters, numbers, spaces, and punctuation marks) but no special graphics.

A Texinfo file is a plain ASCII file containing text and @-commands (words preceded by an `@') that tell the typesetting and formatting programs what to do. You may 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 section Using Texinfo Mode.)

Before writing a Texinfo source file, you should become familiar with the Info documentation reading program and learn about nodes, menus, cross references, and the rest. (See Info file `info', node `Top', for more information.)

You can use Texinfo to create both on-line help and printed manuals; moreover, Texinfo is freely redistributable. For these reasons, Texinfo is the format in which documentation for GNU utilities and libraries is written.