This is a Chip-8 emulator I made back in 2005 as a learning exercise. I recently dug it out and tried compiling on my mac. Lo and behold with only a few simple tweaks (Changed GLUT header file, and use afplay instead of apply) it works!
To compile:
gcc -framework GLUT -framework OpenGL *.c -o chip8
To run:
./chip8 games/Brix.ch8