Apache Vysper 0.5
Apache Vysper is a modular, XMPP server product based on the MINA network application framework.
Vysper 0.5 ships with Multi-User Chat and Publish-Subscribe extensions enabled, and contains partial implementations of specifications including RFC 3920 XMPP Core and RFC 3921 XMPP IM. See the Release Notes for more information.
Please note that Vysper does not yet implement the entire XMPP specification and stack.