A non-trivial number of contributions to Wine come from CodeWeavers (30%+ of all commits), which in turn is funded by its work on Crossover, Proton, and commercial agreements with other businesses. Wine would not be the project it is today without the contributions of CodeWeavers. Contributing cash to the companies contributing code is a perfectly adequete form of giving back.

CodeWeavers released an annoucement when Gaming Portal Toolkit was announced.

https://www.codeweavers.com/blog/mjohnson/2023/6/6/wine-come...