S3 explicitly changed their license to allow copying the S3 API. I forget the year, ~2010? I was working an S3 at the time and it was a strongly debated decision.
Google’s initial launch of their cloud storage copied not just the S3 API, but also the error codes.
I think the point is that if this case had gone the other way this kind of open licensing would happen a lot less. Companies would be obliged to enforce API copyright to protect themselves from loss of copyright (share holder value)
Google’s initial launch of their cloud storage copied not just the S3 API, but also the error codes.