Sound emulator

Audio Overload

　Video Game Music Player
　http://www.bannister.org/software/ao.htm

M1

　Arcade Music Player
　http://www.bannister.org/software/m1.htm

PSFPlay

　a small PSF/SPC player for Mac OS X
　http://tmkk.undo.jp/psfplay/

Game Music Box

　Game Music Box plays video game music files.
　http://www.slack.net/%7eant/game-music-box/

Game_Music_Emu

　http://www.slack.net/~ant/libs/audio.html#Game_Music_Emu

Cog

　http://cogx.org

SIDPLAY

　SIDPLAY is a Commodore 64 music player.
　http://www.sidmusic.org/sidplay/mac/

SIDekick

　http://www.fruitz-of-dojo.de

XSC

XSC is a Mac OS X music player for the Atari ST SNDH fileformat and the SC68 container format.
http://xsc.atari.org

UADE

　Unix Amiga Delitracker Emulator
　http://zakalwe.fi/uade/

S98Player

　http://blog.hiroaki.jp

Mednafen

　http://mednafen.sourceforge.net
　http://sourceforge.net/projects/mednafen/