[July 5th 2005] The 'docs' directory contain various text files that should help you understand the most importants classes in MediaWiki. API documentation is sometime generated and uploaded at: http://svn.wikimedia.org/doc/ You can get a fresh version using 'make doc' or mwdocgen.php in the ../maintenance/ directory. For end user / administrators, most of the documentation is located online at: http://meta.wikimedia.org/wiki/Help:Help