fheroes2 is a recreation of Heroes of Might and Magic II game engine
N64 Game-Engine and Editor using libdragon & tiny3d
The fastest AI powered Aimbot
OptiScaler bridges upscaling/frame gen across GPUs
GZDoom is a feature centric port for all Doom engine games
A tool for converting Xbox 360 shaders to HLSL
UZDoom is a feature centric port for all Doom engine games
Compatibility tool for Steam Play based on Wine and other components
Multi-platform Engine for Desktop, XBOX (UWP) and Mobile games
3D Procedural Game Engine Using OpenGL
High-efficiency minimalist C++ wrapper for OpenGL 4.3
Open source simulation game based on Transport Tycoon Deluxe
3D game engine with lua scripting
A game engine with an emphasis on real-time cutting-edge solutions
Open 3D Engine (O3DE) is an Apache 2.0-licensed multi-platform 3D
Flax Engine, multi-platform 3D game engine
scene-oriented, flexible 3D engine (C++, Python, C#, Java)
FlightGear Flight Simulator: free open-source multiplatform flight sim
A free transportation simulator game
3D Engine c++
xBRZ: "Scale by rules" - high quality image upscaling filter by Zenju
Opensource Created Custom Viewers For Virtual Worlds like SecondLife.