This document was made using DocBook. DocBook is an XML DTD for making structured documents. Practice what you preach, so to say. Editing was done with the emacs editor, which has support for working with XML files. Diagrams were made with Dia, still very much in beta, but freeware (as opposed to the horribly expensive Rational Rose and the likes of it). Images were made with Gimp. All editing, programming and diagram drawing was done on Linux, unbeatable for this kind of work, especially for the server-side Internet programming.