4.19dev (Vulkan) / 03-11-2019
WineD3D For Windows is a DirectX 1-11 to OpenGL wrapper with almost full implementation of DirectX used in Wine. Even if Windows supports DirectX natively, using WineD3D can enhance backwards compatibility with older games, especially on Windows 8+ that don't support 16-bit screen modes. Others possible values include eliminating unsupported versions of DirectX, or porting DirectX applications to OpenGL without having to rewrite the rendering code. That said, it's far from perfect...
Read the readme file, if you're using DirectX 1-7 games!
64-bit builds are for 64 bit apps on Windows 64-bit. For old games, use the regular build on Windows 32-bit or 64-bit.