Pietro is a project mainly written in Haxe, based on the GPL-3.0 license.
PIETRO (Reddit Game Jam 06 - Energy)
Pietro Is Eager To Run Off is a physics-based locomotion game in the spirit of QWOP. You must help Pietro reach the other end of the level by controlling his legs and using the least amount of energy in the process.
You need to install haXe (readily packaged in several Linux distros) in order to compile the game into a runnable SWF. The physics code is Box2Dhx, the haXe port of the AS3 version of Box2D.
The game is also playable online.