3D game engine/framework in C, with Luajit and Python bindings now
Go bindings for raylib, a simple and easy-to-use library
An OpenGL RTS game engine written in C
A modern, cross-platform Quake game engine based on FitzQuake.
DOOM / Heretic / Hexen source port with enhanced graphics and UI
Cross-platform 2D and 3D game engine
3D Game Engine
A basic 3D environment with a first-person POV
3D game engine for C and C++
Tactical, turn-based game engine, that uses OpenGL and WinAPI
A complete 2D Game Engine with built in drag and drop editor
A DirectX based graphics/physics engine