With this emulator you can connect four units at once and can connect them in pairs via an emulated link cable. This means you can play multiplayer Gameboy games

Features

* Supports Gameboy, Gameboy color and SuperGameboy games.
* Runs up to 4 gameboys side by side!
* Gameboy 1 and 2 are linked with a link cable, so are gameboy 3 and 4.
* This linking works for pokemon trading!

Download
Source- Wiibrew

List of Problems

-Zelda: Link's awakening seems to be dog slow.
-Speed for other games is to high.
-Supergameboy support isn't perfect, but works ok for pokemon.
-Kirby's dreamland 2 doesn't do anything.
-Sound sometimes has a high pitch in it which should be there.
-Graphics in zelda intro and ninja gaiden shadow (AKA Shadow Warrior, AKA Ninja Ryuukenden) are messed up at a few places.
-No scaling options.
-No button config options.
-No other controller support then wiimote.
-Saves to the same location as the ROM is loaded from.