To me it seems like a kind of Wine staging, with patches not ready to be merged into the Wine mainline, yet could make some game run or run better. Over time a

To me it seems like a kind of Wine staging, with patches not ready to be merged into the Wine mainline, yet could make some game run or run better. Over time as the code is proven in production and/or is cleaned up to upstream standards, it can be merged to upstream Wine, reducing the difference. Also IIRC there are some other pieces that are not (yet?) part of Wine, that are distributed with it, such as the various DirectX->Vulkan translation layers.