I like to listen to Amiga MOD files. I wanted to listen to them on my iPod, and porting "MikMod" was the
best way to accomplish this.
I integrated MikMod into the iPodLinux gui app, "podzilla" so that it would play these music modules. It was shaky at best... It is difficult to debug software running on the iPod. I basically got it to a point where it worked good enough for a long period of time before it crashed, and just ran with that as my final release.
Since then, a new version of podzilla (podzilla2) has been created, which uses a modular approach, and the current line of thinking is to add MOD support back in using MikMod, but this time doing it via a module which can be loaded if the user desires.