Nuvie is an open source engine for Ultima 6, Martian Dreams, and The Savage Empire. It uses the original data files from the games.
OpenXcom is a new engine for the old game UFO: Enemy Unknown (X-Com: UFO Defense in the USA),
a popular strategy videogame made by Mythos/Microprose in which you take control of the X-Com
organization to fight off the alien menace invading Earth.
An RPC framework for distributed computing.
A game which looks like a Rubik's Cube, but is a slider, not a twister.