One of the largest IRC
networks still in existence with a laid back administration
that provides minimal services but doesn't overwhelm
the users with hundreds of *Serv bots. The primary service
is X, the channel bot, who provides many options for managers
and ops alike.
Undernet is very involved with its users, and holds frequent classes and interesting discussions or interviews
in the #class channel. Channels are very hard
to register, and therefore if a channel is registered, then it is garunteed to be lively. It has frequent netsplits, but not quite to the caliber
it a much more solid network. In general, the help channels on Undernet are often nicer
and more humble than EFnet, but still don't be surprised if you get banned for an arbitrary
reason. There's always room for improvement.