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.
Gnome Simple Stateful Music Player is a small, simple music player that keeps out of your way whenever possible. It remembers what you were playing when you exited, and continues in the same place the next time you start. It doesn't build a database of your audio tracks: instead it works with your files and directories directly. It remembers tracks you have been playing recently, and allows you to pick them up where you left off.
Unix Amiga Delitracker Emulator (UADE) plays most Amiga music file formats by simulating Amiga hardware and software. It plays approximately 200 Amiga music file formats. It provides a command line tool for playing, but it also provides music player plugins for XMMS and Audacious. For other music players, there is a FUSE filesystem that transparently converts Amiga songs to WAV files.
Minirok is a small music player for the K Desktop Environment. As its name hints, it's modelled after Amarok, but with a reduced set of features. In particular, it is designed to cover all the needs and wishes of the author, leaving everything else out. The look and feel is almost identical to Amarok's, though. The main interface is a tree view of the filesystem, with a playlist that can only be populated via drag and drop. There is no collection built from tags, so it's targeted at people whose collections are already structured in a tree at the filesystem level. Searches can be performed both in the tree view and the playlist.