Technologies comparison

[Thomas Burke]

Hi,
I'm studying technologies around portal and social network development. I'm interested in portal frameworks and widget containers. I'm looking for comparison between these technologies but I don't find any recent one.
I'm also particularly interested in OpenSocial APIs, Apache Shindig, OSDE, Apache Pluto ou eXo Platform.
Do you have any recent feedback on that kind of technologies? Or another else to suggest?
Another question: do you know any competitor to Apache Shindig?

[Guy deLyonesse]

Liferay is a pretty good open source portal/portlet container with built in support for databases, E-mail, SSO and persistence. The Community Edition is a free download and can be obtained in a bundle with app containers like Tomcat or JBoss.