facebook messenger

Monitor weather for locations of your Facebook friends.

Adds a badge displaying unread notifications in Facebook.

Desk Client that connects both Twitter and Facebook

Menubar item provides Growl notifications of Facebook events.

Sync your Facebook Events with iCal.

Download Facebook profile pictures to Address Book cards.

Easy, no-cost messenger.

Top Secret Messenger.

Internet phone and instant messenger (was SIP Communicator).

OpenC6 is a Linux and Mac OSX free instant messenger.