0 A.D. (pronounced "zero ey-dee") is a cross-platform real-time strategy (RTS) game of ancient warfare. It's a historically-based war/economy game that allows players to relive or rewrite the history of ancient civilizations, each depicted at their peak of economic growth and military prowess.
Quabro is an arcade game in which the goal is to destroy colored blocks with a ball using four paddles on each side of the screen to steer the ball and keep it on the field. It is inspired by Breakout and Arkanoid, as well as several of clones created later. It is written in Python using the Pygame library.
The Brick Engine is a fast and simple lo-fi gaming engine. The engine provides a comprehensive API, including dazzling visual features, song playback, and collision detection: everything you need to make games with quickness and ease. The engine provides a straightforward C API and has language bindings for Tcl and Pascal, with support for more languages on the way.