Liferay is an Open Source portal platform. It supports JSR-168 and comes with many useful bundled portlets. I've evaluated eXo and JBoss Portal and nowadays I think Liferay is better as a whole.

I started working with Liferay through my involvement in the EducaMadrid (spanish) project. Since then I've been able to know the code well, meet it's main developer Brian Chan and contribute several interesting functionalities and ideas such as using the portlets to build websites, themes, etc.

• Home page: http://www.liferay.com