burnCDDA is a console frontend to cdrdao, cdrecord, MPlayer, mpg321, oggdec, mppdec, flac, normalize, and mp3_check. It can be used to create audio CDs from an M3U playlist (the playlist format of XMMS and amaroK) or from files inside a directory. It supports MP3, OGG Vorbis, Musepack, FLAC, WMA, M4A, and WAV files, and it might be the easiest way to copy an audio CD.
GeeXboX is a standalone media player Linux distribution, similar to MoviX. It's a small bootable CD that allows you to play your favorite video (DivX, XviD, H.264, MPEG 1/2, VCD, DVD, OggMedia, Windows Media, RealMedia, etc.) and audio (MP3, Audio CD, Ogg Vorbis, FLAC, MPC, etc.) files. It also supports networking, and is able to play media from Windows/Samba share, NFS, UPnP A/V Media Servers, RTP/RTSP servers, or SHOUTcast. It supports TV-out, TV tuners, DVB cards, and WiFi cards. It is based on MPlayer, and can be used on any x86, x86_64, or PowerPC computer. It's easy to modify the source to build your own GeeXboX or use an alternative boot method.
SlimServer on DiskStation is an add-on package to the Synology DiskStation family of PowerPC and ARM9 based NAS devices providing the environment to run SlimDevice's SlimServer on it. It integrates into the DS administrative Web interface and comes with various user-friendly tools and scripts to maintain the installation. It supports all currently official features of Slimserver, such as Asian character display and on-the-fly transcoding of various music file formats. Popular third party plugins are supported as well.
Shmplayer executes a single instance of mplayer in the background and controls it through a FIFO. It supports many of the features you'll find in XMMS and it is easily extendible. However, unlike XMMS, shmplayer doesn't require an X server to be active. You can even use it from a remote shell. Shmplayer has also some unique features like "jgrep" that lets you jump to the first "grepped" match of the playlist.