This player is a must have for XMMS if you like modules. I know modplug from my windows time, where it was quite nice to have because Winamp messed up a lot of modules.
For XMMS the builtin mikmod modplayer just sucks. Half of my modules are played wrong or not played at all.
All in all, modplug correctly plays most of them and also plays them right. Very nice :)
An open, cross-platform journaling program.
A scientific plotting package.