Proton is mostly a fork of wine with some not-yet-merged patches, combined with preinstalled dxvk (dx11 implemented in vulkan). AFAIK patches flow both ways.

> dx11 implemented in Vulkan

Also 9 and 10, FYI. DXVK targeted 10/11 initially, and merged in D9VK (a separate but similar project covering DX9) about a month ago.

Proton also has a branch that bundles in VKD3D (Vulkan layer for DX12), but that's still experimental at this point.

IIRC Proton is subcontracted out to Codeweavers, who are also known for making a commercial fork of Wine called Crossover (I should mention they're really good about upstreaming improvements back into Wine— I haven't looked at the numbers but I wouldn't be surprised if most of the commits in Wine were coming from Codeweavers employees)

If I recall correctly, Codeweavers does most development of Wine, Crossover is just the commercially licensed + support version of the product.

Proton is a 'distro' of Wine that includes DXVK and is tuned to support games first and foremost. DXVK is a 'regular' Windows program translating DirectX to Vulkan, which makes enables a sort of pass through of that API.

Do you know what is the deal with DXVK being separate from upstream WINE?

DXVK is a windows program that thus runs on Wine also. It would make sense to include/merge it into Wine at some point, since that is its target, but AFAIK DXVK doesn't even link to anything Wine specific and it thus a completely separate codebase.

DXVK is not intended to be merged into wine. It's written in c++, and prioritizes usability over accuracy.

It isn't intended to be merged, but it is intended to be used with Wine. As such, one can envision it being provided by default with Wine.

Yes, Proton is based (and rebased) on upstream Wine and Proton changes are normally upstreamed too, unless they can't be accepted for some reason.