The IETF uses Jabber for instant messaging during working group meetings, as does the IAB for its own teleconferences and meetings. Since I didn’t really feel like shopping around for a Jabber account, and XMPP integration with Google Talk shut down in the middle of the decade, I decided a few years ago to run my own server, which I pretty much only use for connecting to IETF conference rooms and for chatting with IETF folks as a backchannel during meetings.