There are two version of Trillian, free and Pro. I've been a Pro subscriber since December and I kind of regret it. Trillian takes up many resources, and has many design quirks. Gaim is another free solution on the windows side. I think Adium is better than either Gaim or Trillian. Adium is actually based on Gaim.
Here are the links:
http://gaim.sf.net
http://www.trillian.cc
Here are the links:
http://gaim.sf.net
http://www.trillian.cc




