Tiki is a CMS/Groupware which offers a large number of features "out-of-the-box" arguably more than any other Open Source Web Application. It can be overwhelming, even to an experienced user or administrator.
Tiki has all the classic CMS and portal features of other applications, but also includes features not available anywhere else. Tiki is highly configurable and modular; all features are optional and can be administered through Tiki's browser-based interface.

Tiki has the features you need:

• Wikis (like Wikipedia)
• Forums (like phpBB)
• Blogs (like WordPress)
• Articles (like Digg)
• Image Gallery (like Flickr)
• Map Server (like Google Maps)
• Link Directory (like DMOZ)
• Multilingual (like Babel Fish)
• Bug tracker (like Bugzilla)
• RSS feeds (in & out)
• Free source software (LGPL)

And much more...