NSF

HardNES
External player for the format, with pictures and information by the creator.
http://www.tripoint.org/kevtris/Projects/hardnes/index.html

NEZamp
NSF plugin for Winamp that supports many on-cart sound producing devices in Famicom carts.
http://nezplug.sourceforge.net/

NSF Collection
Specification, information, players and links relating to the format.
http://www.tripoint.org/kevtris/nes/nsf.html

NSFten
Player for Windows, includes information, downloads and files.
http://tnse.zophar.net/NSFten.htm