Flax Engine, multi-platform 3D game engine
Command & Conquer: Remastered Collection
Powerful, mature open-source cross-platform game engine for Python
An open source re-implementation of RollerCoaster Tycoon 2
The Playstation 2 emulator
3D Procedural Game Engine Using OpenGL
Lightning fast C++/CUDA neural network framework
Network gamepad/joystick
A free Chess program for Windows with a large set of features
FPS Unlocker for Roblox
MIT Licensed Open Source version of Torque3D from GarageGames
Opensource crossplatform Fallout 2 game engine writen in C++ and SDL
Advanced Minecraft auto-clicker made in C++
Viewer and exporter for Unreal Engine 1-4 assets
Vivid is a modern C++ 3D engine using OpenGL4+
Amazon Lumberyard is a free AAA game engine
Opensource Game Studio
Dungeon free resources (terrain & roguelike generation)
Visual Studio .vc[x]proj to CMakeLists.txt (make, Ninja ...) enabler
Intrinsic is a Vulkan based cross-platform game and rendering engine
Mobile Device Detection for C and C++
.NET wrapper for the Irrlicht Engine