SEF functionallity has moved to a Bot in Joomla! 1.1.x. Supports sef_ext.php files for advanced SEF URLs. This Bot modifies urls to have advanced SEF URLs. Official Joomla! Addons: These are Components/ modules/mambots that will eventually find their way into the core. They are released early as an Addon to allow for early adoption by 3PD's and to allow people to implement functionality into Joomla! 1.0.