Jabber

The IETF standard for instant messaging, still trying to make it in the real world.

• Locus, an experimental social interface with oodles of relationship visualization options (and Bayesian classification of your buddies).
• msn2jabber, a SOCKS proxy that allows MSN clients to talk to a Jabber server.
• Jabber.org
• jabberpy - for Python
• MIDP clients:
• MGTalk - Google Talk-enabled.
• Client source
• mobber