Open source portal

Liferay has a nice feature list.

• Out of the Box Portlets
  Liferay provides many useful portlets: Blogs, Calendar, Document Library, Journal (CMS), Image Gallery, Mail, Message Boards, Polls, RSS, and Wiki.
  Portals are only useful so long as there are portlets that provide functionality. Our bundled portlets are a great starting point for a portal deployment. They also serve as a large code base of examples from which you can glean patterns on how to write portlets.