This site is maintained by
Temple of Mathematics, but the variou.chat rooms and forums aren't unless specified.
Chat Rooms
MainPage - EFnetMath. EFnet IRC mat.chat room (oldest on Internet).
Freenode Math Wiki. Freenode IRC mat.chat room (largest on Internet).
IRCnet broke off from EFnet and has a mat.chat room (link to the left) but no homepage.
Undernetmath's Weblog | The friendly mat.chat on IRC. Undernet IRC mat.chat room.
Forums
Forums | planetmath.org
The Math Forum @ Drexel University
Math Help Forum
Usenet sci.logic newsgroup. Has discussions of mathematical logic.
Usenet sci.math newsgroup
Usenet sci.math.research newsgroup