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
CedarSync is a real-time collaborative text editor. The text editor allows for the opening and saving of either plain-text or formatted text. It also includes a chat window to allow for a chat discussion to go on while editing a shared document.