We have existing mail, calendar, and IM infrastructure (based on IMAP, SMTP, LDAP, XMPP, iCal, etc) that we're not willing to part with (we've spent 6+ years building it, and for the moment its further along than Zimbra can provide). However we're very interested in the client - we've been prototyping something similar and its going to take a long time to get it to where we want it.

Obviously, with the source available, its possible to take the client and hook it up to our existing infrastructure. I'd like to know how difficult it would be to do this. I've read your whitepaper docs, but haven't had chance to dig into the code yet.

What would be really great for us would be documentation of the XML protocol used by the client to talk to the servlets. We're a Perl shop here, and it wouldn't be a difficult task for us to replace the servlets with a light Perl layer that arbitrates between the client and the backend servers. Is any kind of documentation like this available?

Congratulations on an excellent product. We look forward to experimenting with it and hopefully, if its suitable, contributing code back to the project