Wolfenstein 3D

Wikipedia
 * https://en.wikipedia.org/wiki/Wolfenstein_3D

Wikia GitHub
 * http://wolfenstein.wikia.com/wiki/Wolfenstein_3D
 * https://github.com/id-Software/wolf3d
 * https://github.com/id-Software/Wolf3D-iOS
 * https://github.com/id-Software/wolf3d-browser