SABnzbd Plus is a free/open-source cross-platform binary newsreader written in Python.
A UBB-style discussion board written in PHP. It includes many messaging features, private forums, and robust themes.
Originally written for Wikipedia. It is now used by several other projects of the non-profit Wikimedia Foundation and by many other wikis.
GLPI is the Information Resource-Manager with an additional Administration- Interface.
Manage databases, tables, fields, relations, indexes, users, permissions, and execute any SQL statements.
The state-of-the-art publishing and blogging platform with a focus on aesthetics, web standards, and usability.