XMMS lives on as Audacious: https://audacious-media-player.org/
You can still configure it to look like XMMS.
XMMS1 source code is also still around https://github.com/csepulveda/xmms1
..and XMMS2 apparently had a few recent releases https://github.com/xmms2/xmms2-devel
XMMS1 source code is also still around https://github.com/csepulveda/xmms1
..and XMMS2 apparently had a few recent releases https://github.com/xmms2/xmms2-devel