http://www.linux.org/docs/irc.html http://www.irc.org/

http://alfs.linuxfromscratch.org/misc/irc.shtml

A widely used console based client is irssi, http://www.irssi.org/

and a widely used X based client is X-Chat. http://www.xchat.org/

http://serverwatch.internet.com/ircservers.html