Oracle and Google's fight over the latter's reimplementation of an API was a long haul, and things often looked hairy due to the complexities involved and the difficulty of defining the differences between interfaces and executable code, then matching that distinction to the sprawling convolutions of intellectual property. But the Supreme Court came to the right decision (PDF), yesterday, determining that Google's implemenation of Java APIs was fair use. Though the verdict did not specifically rule that APIs were generally uncopyrightable…
This decision gives more legal certainty to software developers' common practice of using, re-using, and re-implementing software interfaces written by others, a custom that underlies most of the internet and personal computing technologies we use every day.
APIs are the commands and other digital controls that allows two programs to talk to each other. A simple example would be the Twitter commands that let any old app post status updates or do searches on Twitter, without having to use the website. The legal fight was over the API built-in to Java, a programming language that came into Oracle's possession, which Google replicated.
As APIs are functional, not expressive, they should not be copyrightable. 10-year legal battle. QED.