Mamblog
Mamblog is a user blog component that allows you to run a page where users can register and get their own blog page where they can add new blog entries. Features includes archive functionality, html editor support, archives, SEF links, user comment support, ability for users to change blog entry appearence, online editing of configuration options for the admin etc. The component is also translated into several different languages. Mamblog requires Joomla! v1.0.x or Mambo 4.5.2.3 to run.