W4A Engine
WCarmageddon: Reincarnation
WBlend4Web
WBlender Game Engine
WBuild (game engine)
WC4 Engine
WCafu Engine
WParadox Development Studio
WCryEngine
WCrystal Space
WCube 2: Sauerbraten
WDelta3D
WId Tech 4
WDim3
WParadox Development Studio
WGDevelop
WGodot (game engine)
WGoldSrc
WHorde3D
WId Tech
WId Tech 3
WId Tech 4
WId Tech 4
WId Tech 3
WLeadwerks
WLithTech
WOHRRPGCE
WOpenMW
WPico-8
WQfusion
WQuake II engine
WSpring Engine
WStencyl
WUnity (game engine)
WUnreal Engine