If Google wins Google v. Oracle America then would creating API compatible software clones be legal?

Question

As of this writing, the Google v. Oracle America case over some of the Java APIs is set for argument on Wednesday, October 7, 2020 in the US Supreme court. If Google wins the case will that mean that it will be legal to make API compatible clones of software? That is, would the creation of an API compatible clone of a different developer platform, say a popular game engine such as the Unity game engine, be legal?

I'm imagining someone creating a platform where programs originally written against one platform, could be easily ported to a different platform in a similar manner that programs that only relied on the Java APIs Google re-implemented could be easily ported to Android. One could imagine giving developers a better platform licensing deal, (maybe even making the new platform open-source,) or providing other incentives to switch to the new platform.

If Google wins the case, do we know whether or not examples like this one would definitely be affected, or, definitely would need further legislation? Or would it depend on exactly how the decision is reached?

Answer 1

We can't really know until the ruling is made. The Supreme Court might issue a ruling that encompasses all software APIs, or may predicate its ruling on this more specific situation, e.g. that because Oracle's library is so extensive its structure can be copyrighted even if that does not necessarily mean that any individual function signature can be copyrighted. They could also decide based on something unrelated to the heart of the copyright question - skimming through the petition for a writ of certiorari, they could make a decision based on the original implied license from Sun, for example. Hopefully their decision will answer the copyright question of function declarations completely, but it isn't required to.