Xonotic - Xonotic is a free (GPL), fast-paced first-person shooter that works on Windows, OS X and Linux.
mult.dev - Create engaging travel visualisation videos
Quake - Quake is a series of first-person shooter video games released by id Software.
Knightscope - Autonomous robots that predict and prevent crime
Counter-Strike - Counter-Strike is a PC-exclusive FPS video game developed by Valve Corporation.
The Visualization Universe - Catalog of all chart types and tools to build them