Mark Dain Who here uses XMPP/Jabber? FastMail has a chat service that uses it but I don't know much about it. I hear about XMPP a lot though.

Martijn I gave XMPP a try, it is probably the highest recommended chat protocol over at prism-break.org. But I never really got into it and found it hard to convince others to join in. Google's chat in the Gmail sidebar used to use XMPP, so did/does Facebook's. The protocol is solid but I see it used very little outside those gated communities.