[robn_fastmail]

> JMAP server implementations probably will require a good database, not just a dumb FS like in remoteStorage.

To do JMAP well you need to be able to calculate change sets, which does mean a database, though a fairly light one. I think you could do a server without delta updates by always returning a cannotCalculateChanges error in response to getUpdates calls, but it would be very inefficient on both the client and the wire.

> However, I would like to collaborate wherever possible.

Sure! Best place to start is probably the jmap-discuss list:

  https://groups.google.com/forum/#!forum/jmap-discuss