Diligent Engine is a lightweight cross-platform abstraction layer between the application and the platform-specific graphics API designed to take advantages of next-generation APIs such as Direct3D12 and Vulkan, while providing support for older platforms via Direct3D11, OpenGL and OpenGLES. Diligent Engine exposes common front-end for all supported platforms and provides interoperability with underlying native API. Shader source code converter allows HLSL shaders to be used on all supported platforms and rendering backends. The engine is intended to be used as a graphics subsystem in a game engine or any other 3D application, and supports integration with Unity. Diligent Engine is distributed under Apache 2.0 license and is free to use. Alternatively, you can get master repository fisrt, and then individually clone all submodules into the engine's root folder.