[pavon]

No, they ruled that APIs are copyrightable, but that Google's re-implementation was fair use. Based on the reasoning of the decision one would expect that in most cases independently reimplementing an API would generally be fair use. However, from a practical point of view, if you are defending yourself in a copyright lawsuit, fair use decisions happen much later in the process and are more subjective.

Furthermore, CUDA is a language (dialect of C/C++) not an API, so that precedent may not have much weight.

[hedora]

In the end, google reimplemented Java, and the supreme court ruled on a very narrow piece of the reimplementation. I think it came down to a former sun/oracle employee at google actually copy pasting code from the original java code base.

I'm reasonably sure they could reimplement CUDA from a copyright / trademark perspective. It's possible that they could be blocked with patents though.

[monocasa]

> think it came down to a former sun/oracle employee at google actually copy pasting code from the original java code base.

IIRC, the verbatim copying of rangeCheck didn't make it to SCOTUS. They really did instead rule on the copyrightability of the "structure, sequence, and organization" of the Java API as a whole.

[COGlory]

Then why isn't Microsoft suing Valve for Proton/DXVK?

[easyThrowaway]

Because they ran their numbers and realized they have more to lose by going against Valve than... amicably find a compromise.

A more aggressive approach was tried during the Xbox 360 era with the Games For Windows Live framework and by removing their games from the Steam store. It ended up catastrophically bad and they had to backtrack on both decisions.

The irony of Proton de facto killing any chance for native linux ports of windows games isn't lost to them, either.

[dotnet00]

MS has been building lots of goodwill with gamers by bringing games to PC and subverting expectations by not being opposed to using game pass on Steam Deck. Suing Valve or trying to shut down Proton/DXVK would instantly burn all that.

[CoastalCoder]

Not sure if this is relevant, but IIUC Proton and Wine implement Windows' ABI, rather than something involving copyrighted header files.

[constantcrying]

Because these lawsuits are costly, a PR nightmare, loosing them is a serious possibility and going around fighting your competition with lawsuits can put you into a bad place with government agencies.

Playing games on linux is not a threat to microsoft. The money they loose on that is miniscule.

[hobofan]

Probably because they don't care?