WAdventure Game Studio
WAllegro (software library)
WJMonkeyEngine
WAssaultCube
WAway3D
WBlender Game Engine
WBlitz BASIC
WCafu Engine
WClanLib
WCrystal Space
WCube (video game)
WCube 2: Sauerbraten
WDelta3D
WId Tech 4
WDim3
WGame-Maker
WGlest
WGodot (game engine)
WId Tech 3
WId Tech 4
WId Tech 4
WId Tech 3
WJMonkeyEngine
WLightweight Java Game Library
WMarathon Trilogy
WOHRRPGCE
WOpenMW
WOpenSimulator
WORX
WPlayCanvas
WQuake II engine
WRen'Py
WSpring Engine
WStarling Framework
WStepMania
WStratagus
WThousand Parsec
WTwine (software)
WWorldForge