TORCS, The Open Racing Car Simulator, is a highly-portable
multi-platform car racing simulation. It can be used as an ordinary car
racing game, as an AI racing game, and as a research platform.
OpenTTD is a clone of the Microprose game "Transport Tycoon Deluxe", a popular game originally written by Chris Sawyer. It attempts to mimic the original game as closely as possible while extending it with new features.
A cluster operating system.
A server operating system with an integrated identity and infrastructure management system.