The Supreme Court recently agreed to decide the legal battle between Google and Oracle that has been going on for a decade. At issue is whether Oracle can copyright the JAVA application programming interface ("API") that Google used in early versions of Android, which has become the world's most-used mobile operating system.  Simplistically, APIs are interpreters that allow software programs written in different languages to communicate - i.e. they allow Facebook, Twitter, Uber, etc. to talk to your smartphone's operating system.  

Google has argued that the APIs aren't copyrightable, relying on long-established law that states you can't copyright the written description of a method for doing something, where the protection for a method of doing something is the proper realm of a patent rather than a copyright.  Twice now the Federal Circuit has overturned district trials, finding that APIs are copyrightable. 

See for good background that has the software and tech industries, and many others on the edges of their seats for this case that has far-reaching implications on software valuations.