Google’s use of the Oracle’s Java programming language in the Android operating system is legal, a federal jury found today in a verdict that could have major implications for the future of software development.

The case, which has dragged on for six years, could have cost Google as much as $9 billion in damages had it lost. But the decision affects more than just Google. The case is important because it helps clarify the copyright rules around what programmers can borrow for their own work. Programmers routinely borrow APIs from existing products either to ensure compatibility between products or simply to make it easier to learn a new product. An Oracle victory could have seriously curtailed that practice, hindering the creation of new software.

Oracle first brought the suit against Google over the use of the Java APIs in 2010. A district court ruled in 2012 that APIs cannot be copyrighted. But in 2013, an appeals court reversed that ruling. Today the jury found that although the APIs were copyrighted, Google’s implementation of them fell under the fair use doctrine of copyright law, meaning the company didn’t need to seek Oracle’s permission to use them.

If that sounds confusing, that’s because it is. It’s hard to explain what an API is to non-developers. Judge William Alsup, who presided over the case, once explained that the Java programming platform is a bit like a bookshelf. The API is essentially the way the shelf is organized, so that programmers can find the exact information they need. Google organized the Android platform in the same way to make it easier for Java programmers to write software for the operating system, the jury found, but, to extend Alsup’s metaphor, wrote all the books on the bookshelf from scratch.

The ruling is good news for programmers in general, but the Electronic Frontier Foundation (EFF) has argued that techies and the public have already lost because of the earlier decision that found that APIs are subject to copyright.

“There is a real cost to defending fair use,” EFF director of copyright activism Parker Higgins wrote in a blog post earlier this month. “It takes time, money, lawyers, and thanks to the outrageous penalties associated with copyright infringement, comes with a substantial risk.”

That means that many companies and individual programmers may shy away from entirely reasonable projects because of the risk of litigation. But today’s ruling, if it stands, could discourage the most frivolous of suits and give developers more confidence that they can borrow terminology and structure from existing products and win in court if their use is ever challenged. Meanwhile, much of the industry has moved on to more permissive licensing for programming platforms, with a eye specifically towards building standards for other companies, including competitors, to develop products upon.

Of course, Oracle could also appeal the case, which means it could drag on for months or years to come.