Oracle wins appeal re Java API copyrightability [pdf]
This is really bad for open source.  A lot of people can now get sued for making compatible API implementations, and their only argument will be whether it is fair use (which is an affirmative defense).IE Say FredCo has C++ and Java clients for their API.  You decide to make and publish a Ruby client. If you use the same Structure, Sequence, and Organization of the API (IE you use the same API), congrats, the court thinks you are infringing copyright.This is the simple version.  Think about compilers and ABI's and SQL extensions and all sorts of things, and you can see this decision is truly terrible for open source.