glTF-SDK is a C++ Software Development Kit for glTF (GL Transmission Format -https://github.com/KhronosGroup/glTF).
The DirectX Tool Kit (aka DirectXTK) is a collection of helper classes for writing DirectX 11.x code in C++
The DirectX Tool Kit (aka DirectXTK12) is a collection of helper classes for writing DirectX 12 code in C++
DirectXMath is an all inline SIMD C++ linear algebra library for use in games and graphics apps