Splay is an audio player, primarily for console use.
It works on Linux systems, currently, and although
it is likely that it can be ported to other similar
unix systems, it has not been tested (as far as I know).
It is written in C++ and uses the mpegsound library,
the code for the actual interface to this library is
not that large (approx 450 lines).
Splay plays MPEG-1 layer 1,2,3 and MPEG-2 layer 3.
WWW Streaming is supported, (e.g. http://www.foo-bar.org/some/kind_of.mp3).
ID3 tags version 1 & 2 supported by external id3 library id3lib (optional)
There is both a command line program and a gui available
for splay. The gui is written with QT, it's by no means
as attractive as XMMS, but it does exist if you want it.