OpenToonz - OpenToonz is an animation program that is a free software version of Toonz, the animation software...
Xonotic - Xonotic is a free (GPL), fast-paced first-person shooter that works on Windows, OS X and Linux.
Synfig Studio - Just another WordPress site
Counter-Strike - Counter-Strike is a PC-exclusive FPS video game developed by Valve Corporation.
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
Quake - Quake is a series of first-person shooter video games released by id Software.