Multiple Arcade Machine Emulator
http://www.mame.dk/ (its dead,man)
http://www.cybertechdesign.net/mameroom/
IRC: EfNet: #roms #mame (small)
Cyberjunks: (irc.cyberjunks.net) #roms Newnet: #emuchina #tosec
Good Tutorials on Mame and more: http://www.mameworld.net/easyemu/