XMMS is a multimedia player based on the look of WinAmp. It plays MPEG layer 1/2/3, Ogg Vorbis, WAV, all formats supported by libmikmod, and CD audio. It has a plugin system for Input / Output / Effects / Visualization, and through plugins it can play many more sound and video formats.
XMMS2 is a redesign of the XMMS music player. It features a client-server model, allowing multiple (even simultaneous!) user interfaces, both textual and graphical. All common audio formats are supported using plugins. On top of this, there is a flexible media library to organize your music.