WIRED.com reports that Google and Oracle are back in court after the later appealed against the decision in a previous suit.

The federal court had ruled in favour of Google after Oracle filed a lawsuit against Google claiming infringement of Java-related patents in Android’s APIs.

The judge originally assigned to the case, Judge William Alsup, went so far as to learn the Java programming language to better understand the technical details of the case, and he eventually concluded that APIs could not be copyrighted. He said that the Java APIs were kinda like the method you would use to organize a library of books, saying that you can copyright the content of the books on a shelf, but not the way they are organized.

Oracle disagreed, and filed an appeal in February, arguing that Google’s use of the Java API was akin to copying the chapter titles and topic sentences of a Harry Potter novel verbatim, paraphrasing the rest, and then trying to pass the whole thing off as an original work.