I'm having a little trouble understanding the distinction. An API is still defined by code though. It's basically just the publicly facing part of the code, right?
You can reimplement a compatible API in a different language that would share no code. This would be a clone, not a copy, as no work from the original author was used. The real issue here is if an API is just an interface, or could be considered code itself.
(IMHO, it's an interface, like a power socket or a light switch. You make it fit, and then it works.)
This seems like a question that has previously been answered and that is why we register software copyright as a literary work. It seems unless actual text was copied, it's not a violation. I've recently started learning more about this, so I could be wrong.
You could argue that API's aren't code -- they are merely descriptions on how to call a piece of code. And those kind of directions are not copyrightable.
It seems if they wrote their own code from scratch but it defined a similar API then that wouldn't be covered by a copyright. My understanding is that is what basically happened when they began treating code as a literary work.
