GoBoy
Multi-platform Nintendo Game Boy Color emulator written in Go
...The program includes debugging functions making it useful for understanding the emulator operation for building one yourself. These functions include printing of opcodes and register values to the console at each step (although will greatly slow down the emulation) and toggling of individual sound channels. GoBoy is compatible with MacOS, Windows and Linux. Building on Windows 10 requires MinGW and on Linux, you’ll need to install gtk.