[AnthonyMouse]

That's the point. The API isn't valuable because of the creative expression (the thing copyright protects), it's valuable because its functionality (the thing copyright doesn't protect) is necessary for compatibility.

Oracle apparently bamboozled the Federal Circuit into deciding that something called the "structure, sequence and organization" of the API should be copyrightable. But of course nobody cares about that part -- the order doesn't matter. You can sort the API into alphabetical order and strip out all the comments and it would make no real difference to anybody. But here is Oracle claiming that the copyrightable part is worth billions of dollars.

[cwyers]

If copying the APIs is only valuable for compatibility, why did Google do it? Android isn't compatible with any Java apps.

[AnthonyMouse]

It's compatible with many Java libraries and IDEs etc. It isn't compatible with Java apps because the UI framework has to be different on a phone. Porting Java apps thereby requires changing only a minority of things rather than everything.

It's like asking why you can write C programs on Windows even though it doesn't provide an X server.

[wcummings]

Libraries, though.