Here is newest version of Trillian 5 Pro for Windows.
Description: Keep in touch with friends and contacts on every major IM and social network. Trillian for Windows’ clean and pleasant user interface has been carefully designed to smoothly integrate with Windows 7. Our newly-supported Foursquare plugin lets you meet up with new friends and discover new places! Stuck on a netbook with a tiny screen? No problem. Switching between our full and compact user interfaces is only a click away.