extranet

The casetracker lets you assign (development) tasks to yourself and others and track the progress on a project. Enable
the Atrium Case Tracker feature and add it in the appropriate group space
or feature preset in private mode.

Open Atrium is an intranet solution from DevelopmentSeed with a group space architecture that is configurable on a group by group basis. Groups and features can be private or public which makes it a perfect primer for intranet and extranet projects. Out of the box It comes with six features: a blog, a wiki, a calendar, a to do list, a shoutbox, and a dashboard to manage it all.