XMPP is a protocol which started out as 'Jabber' and was mainly intended for chat. It's still in heavy use for this purpose today, with its more prominent uses in Google's GTalk and Apple's iChat, but has grown far beyond that. The Jabber community took the effort and made it an IETF standard (RFC 3920 and RFC 3921). What makes XMPP a real workhorse are the many extension to the base protocol which make it an all-purpose messaging protocol.

All standardization is done by the XMPP Standards Foundation (XSF). The XSF very much resembles the ASF. Its members are individuals not companies, membership is granted for those with a proven XMPP track record. All business is completely done in the open. Everyone is encouraged to participate on the mailing lists.

But there are differences. Anyone can apply for membership. Every member must reapply once a year.

So it's a pity there are not so many ASF-licensed XMPP server implementations. That's why I started Apache Vysper over there at Apache Labs.