Collaboration

Open Atrium

Open Atrium (Based off of the Drupal core) is an intranet in a box that has group spaces to allow different teams to have their own conversations. It comes with six features - a blog, a wiki, a calendar, a to do list, a shoutbox, and a dashboard to manage it all.

Gforge

GForge is an extensible platform with an intuitive interface that ties together a huge toolset, from Source Code Management (SCM) to extremely customizable Trackers, Task Managers, Document Managers, Forums, Mailing Lists. All of these are controlled by a centralized permission system and maintained automatically by the system.