The manual is marked up using docbook. We then use the docbkx maven plugin to transform the markup to html. This plugin is run when you specify the site goal as in when you run mvn site or you can call the plugin explicitly to just generate the manual by doing mvn docbkx:generate-html. When you run mvn site, the documentation is generated twice, once to generate the multipage manual and then again for the single page manual, which is easier to search. See Appendix A, Contributing to Documentation for more information on building the documentation.