Trillian is a free fully featured, stand-alone, skinnable chat client that supports chatting on Windows Live, Facebook, Yahoo, MySpace, AIM, Email, Google Talk, Skype, ICQ, Jabber, IRC, and Bonjour. It is a free, but ad-supported instant messaging application that's reliable, easy-to-use, well-designed, customizable and efficient.
Here are some screenshots to illustrate the features and user interface of this application:
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