Audacious Media Player: GUI, Free Software, Player (application software), POSIX

Beep Media Player: Audio Player (software), Free Software, XMMS, GTK+

XBMC: Free and Open Source Software, Cross Platform, Media player (Application Software)

Music Player Daemon: Daemon (computer software), Database, Media (application software)

Volume Logic: Media Player (Application Software), iTunes, Plantronics