Magnum
Lightweight and modular C++11 graphics middleware for data and games
...And it’s free to use, even for commercial purposes. Among Magnum essentials is a UTF-8-aware OS, filesystem and console abstraction, a versatile vector math library and a slim C++11 wrapper of Vulkan and OpenGL API families. Build on top of that or opt-in for more. Shaders and primitives for fast prototyping, algorithms, debugging and automatic testing, asset management, integration with popular windowing toolkits and a UI library. Everything fits together but you still have a choice. ...