You can use this IRC server for testing: 162.246.156.17 port 12399

IRC client I'm using (web-based):

https://kiwiirc.com/

Some useful links re. IRC protocol:

http://chi.cs.uchicago.edu/chirc/irc_examples.html

http://archive.oreilly.com/pub/h/1963

http://blog.initprogram.com/2010/10/14/a-quick-basic-primer-on-the-irc-protocol/