Derby
MVC framework making it easy to write collaborative applications
...Derby includes a powerful data synchronization engine called Racer that automatically syncs data among browsers, servers, and a database. Models subscribe to changes on specific objects, enabling granular control of data propagation without defining channels. Racer supports offline usage and conflict resolution out of the box, which greatly simplifies writing multi-user applications. Derby applications load immediately and can be indexed by search engines, because the same templates render on both server and client. ...