Emulation libraries
From
NESdev Wiki
Source code for several NES console emulators and NSF music players is available.
NES Emulators
FakeNES
FCEUX
Nessie
Nestopia
Nintendulator
UberNES
VirtuaNES
NSF Players
Game Music Box
Game_Music_Emu
NEZplug
Nosefart
NotSoFatso
NSFPlay
XMMS NSF
See also
Emulators