RealBoy is a Free, Fast, Yet Accurate, Game Boy/Game Boy Color
Emulator for Linux/Unix.  It has both technical as well as educational
goals.

Technically, it aims for the following:

1) Accuracy. Perhaps the most important technical goal, as seen in
the best closed-sourced emulators, such as KiGB and BGB, and some
free emulators, such as Gambatte and MESS.

2) Performance. Show that it is possible to implement a very fast
emulator without sacrificing accuracy.

3) Feature-rich. Implement advanced features such as a flexible
internal debugger.