I don't know the state of the project, but while researching OT stuff for Firepad, I came across https://github.com/sveith/jinfinote https://github.com/sveith/j

I don't know the state of the project, but while researching OT stuff for Firepad, I came across https://github.com/sveith/jinfinote https://github.com/sveith/jinfinote. It looks like a peer-to-peer OT implementation (I think it requires a server to set up the initial session, but after that, everything could be peer-to-peer [as implemented, the server just relays messages with no processing]).