* [irc://irc.mozilla.org/thunderbird #thunderbird] - Thunderbird project discussion and end-user help
* [irc://irc.mozilla.org/seamonkey #seamonkey] - Community project to revive the bundled application suite
* [irc://irc.mozilla.org/calendar #calendar] - Lightning and Sunbird calendar clients. ''But note that the freestanding Sunbird is at EOL since 2010. Since then only the Lightning calendar (extension for Thunderbird and SeaMonkey) is still actively developed.''
* [irc://irc.mozilla.org/bugzilla #bugzilla] - Bugzilla project discussion
* [irc://irc.mozilla.org/webtools #webtools] - Bonsai, LXR, Tinderbox, and Mozbot project discussion