Amarok (formerly known as amaroK) is an audio player for Linux and other varieties of Unix. It makes use of core components from the KDE desktop environment. It is released under the GPL and is bundled with many distributions that use KDE as the primary desktop environment.
I use iTunes on OS X but I can also listen to music with Amarok when I'm on Linux.
An open source multi-protocol instant messenger application. It is part of KDE for Linux and other Unix-like operating systems and is compatible with AIM, ICQ, Yahoo, Jabber, and other common IM protocols.
A MMORPG that is planned to be released sometime in April 2005. Currently under private alpha testing the game is already over 15,000 square miles (40,000 kilometers) making the total land area, twice the size the state of New Jersey.
The game includes many different skills and races to choose from and is mostly played online with PvP (player versus player) battling in all areas. Also features a realistic weather system and amazing graphics.