> I think by "Copying a functional spec" he meant to say implementing someone else's functional spec, rather than just re-publishing it. So that what's being co

> I think by "Copying a functional spec" he meant to say implementing someone else's functional spec, rather than just re-publishing it. So that what's being copied is not the copyrightable text of the spec, but the non-copyrightable abstract ideas described by the spec. Implementing an API spec is not just using the "abstract ideas" in the spec. It requires copying the specific text of the API: a function named DoSomething will incompatible with one named do_something. I don't think that's a valid way to distinguish copying APIs and implementation. On a purely theoretical basis, I do think APIs could be copyrightable, I don't think there is a valid way to distinguish them from implementation. The main argument against copyrighting APIs is practical: everyone has been doing it for decades, and changing the status-quo will be disruptive. Another practical reason is that copyrighting APIs will decrease competition by impeding companies from creating better drop-in competitor products to established players. But this is really an argument against all software copyright, not just API copyrights.