• MAME - one of my most favorite emulator I tried (Mac:MameOSX, Linux: run from wine)
  • note: please click its “Previous release” link, and download ver0.122b for best old ROM compatibility.
  • instruction: put rom zip file into “roms” sub-folder, run MAME, “tab” key to bring up the button and key configuration;
  • ROM site CoolRom ROMWorld
  • cool roms
    • super mario 3

• little fighter 2
  • notes: a very popular free arcade game made by 2 Hong Kong people.
  • original LF2 version: LF2.net
  • re-inforced LF2 (r-lf2) version (best official mod): alternative download site (video demo)

So as most games only support LAN (local area network) gaming, what if your teammate is not in local, like one in France and one in USA.

Thus, there is a free tool Hamachi, brought over to LogMeIn company, that provides the solution, (create a virtual LAN between your teammates)