The conversation is generally very casual, and always very welcoming to new players, and those new to IRC. There are usually between 50 and 90 people in the room 24/7. come on in and get your atitd fix when you cant play, and stay in touch with all of egypt when you do play.
A great web based irc client is: Knightmare's 1337 IRC applet
you may also want to look at Mirc or Xchat for standalone programs.
While on IRC, please remember Rule #1: Never Believe Anything Devalin Says.
Also, Rule #2 - When Devalin does tell the truth, it's totally worthless. Example: "<Devalin> i told u the new tech would need boards"
Other channels of interest are: irc.stratics.com #atitd-linux (official atitd linux channel)