HDHomeRun IRC Channel:

Server: irc.freenode.net
Channel: #hdhomerun
Java client: Freenode Client

MediaPortal IRC Channel:

Server: irc.freenode.net
Channel: #mediaportal
Java client: Freenode Client

MythTV IRC Channel:

Server: irc.freenode.net
Channel: #mythtv-users
Java client: Freenode Client