Document the protocol

[Oppen]

It may be interesting to make alternative implementations, for example a simpler one that runs under a super-server that would handle the TLS encryption and connection for low load servers or one with pipes that allows for an easier implementation of hooks (e.g. unlocking a per-user encrypted directory on sync and locking it again on exit, for data-at-rest privacy).
However, this currently requires groking the source code, since the protocol description is nowhere to be found.

[jrabbit]

There's extensive documentation that can be found on the RFC page

[Oppen]

Oh, sorry, I couldn't find them.