A new version of Alfresco is ready to be downloaded now!
Alfresco Community 4, the first open platform for social content publishing is now available to download for free. Alfresco 4 includes new tools which allow developers to create social and cloud-scale, content-rich applications. Further, it includes a new, extensible service to publish content and status updates to social sites, including YouTube, Facebook, LinkedIn, Twitter, Flickr and SlideShare.
See details here