This book was created with the LyX document processor, which in turn uses the combined LaTeX and TeX typesetting system. The e-book version was generated using the applications Elyxer (which converts LyX files to HTML) and Calibre (which converts HTML files into e-books), along with a custom script to take care of some formatting issues. All of the applications listed here are open source, and all are highly recommended.
For the printed book, the main text uses the Palatino typeface, while headers and PHP code are in Helvetica, and wikitext and other specialized syntax (XML, CSV etc.) are in Courier.