Google last night strode into the last-chance saloon of the US Supreme Court, warning judges (PDF) that if they did not overturn a Federal Circuit ruling in Oracle's favour over its use of Java code in the Android mobile operating system, it could "upend ... the computer software industry."

"New entrants into a software market 'reimplement' existing tools," argued Google, adding in a plea in the umpteenth appeal in the near decade-long spat that amounts to: "Think of the devs!"

A ruling by this Court that copyright prohibits that reimplementation would allow the authors of older software to hold their users hostage, lest the skills that the users have built up over long periods of time become worthless when they move to a new environment.

It held that Google "reused declarations from the Java SE libraries because — and only because — no other option would recognize the calls used by Java developers".

Google also repeated an earlier argument in the same copyright spat, rejected when the battle was going through the Federal Circuit, that the "merger doctrine" excluded Java's APIs from copyright protection. The merger doctrine holds that "when there is only one way to write something, the merger doctrine bars anyone from claiming exclusive copyright ownership of that expression."

The lower court had previously held (in 2013) that the merger doctrine did not apply because "[t]he evidence showed that Oracle had 'unlimited options as to the selection and arrangement of the 7,000 lines of code Google copied." In other words, that previous ruling stated that the idea and its expression had not merged, because at the time of creation, there had been multiple ways of expressing the former.

Other strands of the Mountain View firm's argument include that the "declarations were highly functional, rather than expressive", and that Google used a relatively small number of the Java APIs proportionate to the Java code base.

How long has this been going on...

The case has now rolled on for nearly a full decade, first kicking off in August 2010 over Google's unlicensed use of Java APIs in Android, by far the most used mobile operating system in the industry, with various stat-botherers saying it runs on at least seven of every 10 smartphones in use globally.

Google bought Android, a Linux mobile OS startup that used Java's class library APIs, in 2005 for a mere $50m, and launched the first phone to use the mobile OS in 2008.

Back in '10, Oracle's original filing - shot off just a year after it acquired ownership of Java when it bought Sun Microsystems for $7.4bn - included a claim for patent infringement, which failed, but the copyright claim was upheld in 2012. Google, which claims its use of the software was covered by the American copyright doctrine of fair use – Big Red contests this – won its case twice in San Francisco federal court. The first time, in 2012, US District Judge William Alsup ruled that APIs, in and of themselves, cannot be copyrighted, before that decision was reversed in the federal appeals court, which found Big Red's Java code was covered by copyright. Emails emanating from Android daddy Andy Rubin himself - shown in court at the time - stated that while working on Android he'd believed that key Java APIs were copyrighted.

Then in 2016, a jury ruled Google's use of copyright materials was fair use – a decision that Big Red duly appealed multiple times before finally having it overturned in 2018.

Happy as Larry: Why Oracle won the Google Java Android case READ MORE

Google tried to appeal this decision, but in August, 2018, the federal court refused to re-hear the case, leading Google to make this last-ditch appeal to the top court in the US, the Supreme Court.

The Supreme case so far

So far, Google has flung amicus briefs from the biggest firms in the software industry, including Microsoft, whose submission ironically argued for third-party developers to be able to access and reuse code in aid of broader "interoperability" between platforms.

Oracle, in a March filing, told the Supremes that the Court of Appeals was correct in holding that Google violated Oracle's copyright when it built a version of Java for the Android OS, and that it was "not fair use as a matter of law".

The US Solicitor General agreed in an October 2019 filing, though Google quickly snapped back that Federal Circuit's fair use ruling was "not free from doubt."

If the court rules in favour of Oracle, the Chocolate Factory will have to cough for copyright damages that Oracle estimated at $9.3bn in 2016, nearly $2bn more than Oracle paid for Sun Microsystems back in 2009. Google spent a fraction of that on Android, then a two-year-old startup founded by Andy Rubin and others, 15 years ago.

Oracle told The Reg: "While Google would prefer to live in a world unencumbered by intellectual property rights, in the real world copyrights are an essential protection and incentive for innovation. Oracle offers several licensing options for Java. Ethical developers and businesses around the world continue to recognize the value of Java and take advantage of our licenses to drive innovation and profit." ®