Here's what he wrote on youtube.
I'd like to thank some people that made this possible (in no particular order):
Guns N' Roses - for a kick-ass song
www.starbreeze.com - makers of FastTracker ][
DOSBox team - DOSBox is the best!
NEStopia team - great emulator
Brad Taylor - for his NES sound hardware docs
www.mega-nerd.com - for libsndfile
Andreas Pedersen - for moral support and inspiration
Rob Mocca - for putting up with my whims all these years
My wife - for letting me waste my time on this crap :-)
Kristofer Dahl - for playing the guitar solo so slooowly that even I could catch all (well, most of) the notes
nesdev.parodius.com - everyone that contributed docs, demos, etc.
This remake was made in Fasttracker ][.Then the XM was converted to my custom NES sound engine format and compiled into a ROM using my NES assembler/linker.
Fun trivia: If you download the ROM you can turn sound channels 0,1,2,3 on/off individually in real-time by using the D-pad.
Click here to download the rom.
This is a serious "jaw dropper", is there even such a term in english? oh well what I mean is that this really kicks ass :-)