I've just finished the converter for OS X.
It can handle .kss file.
You can find a lot at KSS Kingdom.
The player function is not yet done.
A problem of speed with my Macintosh didn't let me supposed that everything will work.
Depending of the song complexity it can need 2 seconds of calculation for one second of wavefile
But for PSG or SCC it's fast enough.

You can take that version at... city-hunter.homeunix.net/valken/kss-x/kssx-current.tgz

Hope the mac community will appreciate this tool.

Regards

Valken