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).<p>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.<p>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.