Reimplementing Software Interfaces is Fair Use

 Somewhat surprising,  and Beyond the US?   Good overview of the technical implications.

Reimplementing Software Interfaces Is Fair Use

By Pamela Samuelson  Communications of the ACM, July 2021, Vol. 64 No. 7, Pages 24-26

10.1145/3466607

A long-standing, generally accepted norm in the computing field distinguishes between software interfaces and implementations: Programmers should have to write their own implementing code, but they should be free to reimplement other developers' program interfaces. This norm, of which Sun Microsystems, the developer of Java, was once the software industry's foremost proponent, is now the law of the land in the U.S. after the Supreme Court's decision in Google Inc. v. Oracle America, Inc., which overturned a lower court ruling that reimplementing an interface infringed copyright.

The Supreme Court took Google's appeal on two issues. One was whether program interfaces are protectable by copyright law. The Supreme Court declined to decide that issue, even though many amicus curiae (friend of the court) briefs filed by software developers, organizations such as the Electronic Frontier Foundation, the Center for Democracy & Technology, and the Computer & Communications Industry Association, as well as numerous intellectual property scholars, supported Google's argument that program interfaces are uncopyrightable.

A second issue was whether Google's reimplementation of 11,500 declarations from 37 Java Application Program Interface (API) packages in its Android smartphone platform was fair use or infringement. Although a jury rendered a verdict in favor of Google's fair use defense after a two-week trial, the Court of Appeals for the Federal Circuit (CAFC) overturned this verdict. The CAFC concluded that no reasonable jury could have found Google's appropriation of that many lines of computer code was fair use. This is the ruling that Supreme Court's decision reversed.

The penultimate sentence in Justice Breyer's opinion for the 6-2 majority succinctly states the Court's conclusion: "where Google reimplemented a user interface, taking only what was needed to allow users [that is, programmers] to put their accrued talents to work in a new and transformative program, Google's copying of the Sun Java API was a fair use of that material as a matter of law."

After explaining Oracle's claims against Google, this column reviews the Court's reasons for rejecting Oracle's arguments on the fair use issue.  ... '