The X Multimedia System (XMMS) is a free software audio player very similar to Winamp, that runs on many Unix-like operating systems.

XMMS currently supports the following audio and video file formats:

* AAC support is provided by the faad2 library, supporting m4a files
* APE Monkey's Audio Codec .ape files - support provided by the mac-port project plugin
* Audio CD, including CDDB via FreeDB lookup
* FLAC support is provided by a plugin in the FLAC library
* Icecast and SHOUTcast streaming supported, and is compatible with Winamp 2 skins.
* libmikmod supported formats (including .XM, .MOD, .IT)
* ModPlug plug-in for playing mod, s3m, xm, umx, it and other famous trackers
* mp3PRO support is provided by a third party plugin (which does not support SHOUTcast title streaming)
* MPEG Layer 1,2 and 3 (Also known as MP3), using the mpg123 library
* Musepack support using XMMS-Musepack plugin.
* OGG Vorbis support is provided by a plug-in provided by xiph.org
* SHN support is provided by a plug-in provided by etree.
* speex high quality & ratio speech compression format via plugin
* TTA support is provided by a third party plugin
* UADE plug-in provides Most Amiga music formats.
* WAV
* WavPack with support provided by a third party plugin
* WMA Limited support provided by third party plugin.