As a bit of extra info, IRC is Internet Relay Chat - basically a chatroom with basic structure, the ability to PM members etc. Quakenet is the server we're using and there's literally thousands of users on thousands of channels there for almost every topic under the sun, #ArmsOfTelos is just one of many 
It's a great place to hang out and talk random topics through, query things - it's cool that JP hangs out there pretty much permanently, makes for a really short feedback loop which is great
But anyway, to connect to it you'll need an IRC client of some description.
Quakenet actually provides its own webchat client usable in your browser:
http://webchat.quakenet.org/
I use mIRC which is a downloadable client:
http://www.mirc.co.uk/
(It says it's a trial but it extends itself beyond it)
Other clients include xChat, Pidgin, etc.