The typesetting program called TeX is used to format a Texinfo document for printable output. TeX is a very powerful typesetting program and, when used correctly, does an exceptionally good job. It is not included in the Texinfo package, being a vast suite of software in itself.
TeX is a document formatter that is used by the FSF for its documentation. It is the easiest way to get printed output (e.g., PDF and PostScript) for Texinfo manuals. TeX is freely redistributable, and you can get it over the Internet or on physical media. See http://tug.org/texlive.