Saros brings multi-writer synchronous distributed editing to the Eclipse IDE, e.g. for joint code reviews, explaining code remotely, or distributed pair programming -- all also for more than 2 participants; we call this Distributed Party Programming. It includes refined awareness functionality, text chat, and a simple distributed whiteboard/sketching facility.
Eclipse Update Site: https://www.saros-project.org/update-site/eclipse
ConneX is a pure p2p collaboration platform based on JXTA technologie. its provides Real-Time collaboration tools in form of Plug-ins (instant messaging, file sharing, chat, whiteboard, slide show)100% Java.