WineD3D For Windows is a DirectX 1-11 to OpenGL wrapper based on WineD3D, which is an almost full implementation of DirectX used in Wine.
Even if Windows supports DirectX natively, using WineD3D can enhance backwards compatiblity with older games, especially on Windows 8 and newer that don't support 16 bit screen modes. Another possible use is to emulate unsupported versions of DirectX, or porting DirectX applications to OpenGL without having to rewrite the rendering code.
Please note that WineD3D is far from perfect, and many games will not work.
Instructions on how to use the DLLs are included.
If you find a bug, please report it here https://bugs.winehq.org/.
Reporting bugs on this page is completely useless! I am not a Wine developer, I'm just maintaining these builds and there's nothing I can about those problems.
Feel free to use the comment section if you need help or just to say thanks.
You may also be interested in Mesa3D For Windows, which provides Software Rendering for OpenGL applications.
Mesa3D For Windows can be used to fix old OpenGL games that have trouble running on modern GPUs.