Cactus is an audio player. It shows all your music files in a kind of database, and you can easily browse, edit, and search your collection. It also supports synchronizing your music collection with a mobile player device. It plays MP3, WAV, and Ogg. It can also import and rip audio CDs, automatically show album covers, tag MP3 files, and maintain a fast library. A GTK 1.x binary is also available.
Cajun is a program that allows you to turn any computer into a massive audio jukebox for your car or home. It uses LCD displays/keypads, and supports infrared remote controls. Soundcard output is delivered to your (car or home) stereo for amplification. The software supports a playlist and shuffle mode.
Chango is a system for cacheing MP3 files from multidisc cdrom drives. Since you can't actually mount different discs in the same physical device simultaneously, this software will cache the files you need off to a predetermined cache, so that all of the needed files will be available simultaneously.
Cjukebox is a curses-based player and manager for audio files and playlists. Its user interface was inspired by the Norton Commander for DOS. It does not rely on a separate database application. Playback is handled by the Musicus tool, which plays all audio formats supported by xmms (wav, Ogg, MP3, Flac, MPC, etc.).