From what I gather, Game Porting Toolkit is two things - a fork of Wine, and their own adaptation/extension of open source projects for DirectX compatibility. Some observations: Windows compatibility: * Windows platform compatibility is achieved with a slightly patched version of Codeweavers' Wine fork - virtually all of the hard work of Windows compatibility has been achieved by the Wine developers and Codeweavers a…
It's sad that D3DMetal isn't open source. Worth noting that this stuff is exactly why people should strongly consider using a copyleft license. It's pretty annoying that nobody can build on top of Apple's work here or incorporate any improvements into DXVK, but that's the license the DXVK project chose.
[1] The license is probably actually meaningless in a lot of jurisdictions, but it still has a chilling effect for commercial parties using it. That's probably exactly what Apple intends.