Yesterday, the Supreme Court sided with Google in a long-standing battle with Oracle over the design of the Android APIs. Specifically the court ruled that Google did not violate US copyright law when it used the Java SE API to create Android.

Russell Brandom and Adi Robert, reporting for The Verge:

“Google’s copying of the API to reimplement a user interface, taking only what was needed to allow users to put their accrued talents to work in a new and transformative program, constituted a fair use of that material,” the Supreme Court ruled in a 6–2 opinion, with one justice (Amy Coney Barrett) not taking part in the ruling. It overturned an earlier federal decision, which found that Google’s use of the API had constituted infringement.

The court’s opinion concludes that APIs — which let programmers access other code — are significantly different from other kinds of computer programs. “As part of an interface, the copied lines are inherently bound together with uncopyrightable ideas … and the creation of new creative expression,” Justice Stephen Breyer writes in his opinion. Unlike many other computer programs, Breyer wrote, much of the copied lines’ value came from developers being invested in the ecosystem, rather than the actual operations of the program. Google used the API to let Java programmers build Android apps, which the court declared is a fundamentally transformative use

This is a great thing for the software industry. Copyrightable API signatures would be a giant unenforceable mess.