Devalot is a social networking application centered around software projects. It connects the user community with the development community and encourages participation and communication. It includes all the features you've come to expect in modern Web-based applications such as tagging, comments, and a wiki, as well as features you'd expect in project tracking software such as ticketing. It has features similar to some of those found in Trac, Collaboa, GForge, Mephisto, and Typo.
WebCit is a Web-based, AJAX-enabled frontend to the Citadel groupware/collaboration system. It is an attractive Web middleware layer that allows user-friendly access. By combining WebCit and Citadel, you can have a versatile online environment with many users concurrently accessing the same system using the user interface of their choice (text, Web, or downloaded client software).
PukiWiki ('PoohKeyWeKey' without any prolonged sounds) is a wiki implementation that works on PHP 4 and 5, outputs XHTML 1.1, has many plugins (including one for bug tracking) and skins (such as one for embedded browsers), enables English and/or UTF-8 configuration, and features case-insensitive WikiNames. The formatting rules are based on YukiWiki.
Pocoo is a bulletin board software (a.k.a. message board). It provides an advanced plugin system with a component architecture which allows other developers to modify Pocoo to their liking without the need to touch existing source code. Because it uses SQLAlchemy, it is possible to use either MySQL, SQLite, Oracle, or Postgres as the storage backend.