Oracle's nearly eight-year legal battle with Google just won't end. Tuesday a federal appeals court ruled that Google violated Oracle's copyrights when it built a custom version of the Java platform for its Android operating system. The court sent the case back to a district court to decide how much Google should pay Oracle. But Google can appeal to the Supreme Court. And it should, because the decision will affect not just Google and Oracle, but the entire software industry.

The decision won't kill Android, the world’s most popular operating system for smartphones. Google switched to a fully open source version of Java starting with the Nougat release of Android in 2016. But it could force many software companies to rewrite parts of their products, even if they’re not using Java or any other Oracle software. That will not only be expensive, but could make applications and services from different companies less compatible. In other words, get ready for more tech headaches and higher software bills if Tuesday’s ruling isn't overturned.

The case revolves around what are called "application programming interfaces," or APIs. To oversimplify a bit, APIs are the way different pieces of software interact with each other. Software companies have long borrowed APIs from existing products to either ensure compatibility between products or to make it easier for programmers to learn new technologies. Google used the Java APIs in part to make it easier for Java programmers to build Android apps without learning an entirely new language. Now companies large and small who’ve taken similar steps could a face a swarm of copyright lawsuits.

"This creates a tremendous incentive for lawyers and copyright trolls to look for litigation," says Electronic Frontier Foundation legal director Corynne McSherry.

Oracle doesn't see it that way. The opinion “upholds fundamental principles of copyright law and makes clear that Google violated the law," Oracle general counsel Dorian Daley said in a statement. "This decision protects creators and consumers from the unlawful abuse of their rights."

Oracle filed suit against Google shortly after its 2010 acquisition of Sun Microsystems, the company that built the Java language and platform. In 2012, a district court ruled that APIs aren't subject to copyright. That decision was overturned by an appeals court and returned to the same district court for a jury trial over whether Google’s use of the Java APIs qualified as permitted "fair use" under the law. In 2016, the jury ruled in Google's favor. Oracle appealed the jury decision, and Tuesday, the appeals court sided with the company.

"We are disappointed the court reversed the jury finding that Java is open and free for everyone," Google spokesperson Patrick Lenihan said in a statement. "This type of ruling will make apps and online services more expensive for users. We are considering our options."

Meredith Rose of the advocacy group Public Knowledge says the case’s tortuous history could bolster Google's case. The appeals court first ordered a jury trial, "then proceeded to say that they disagreed with the jury verdict and substituted their own," she says. "It makes it hard to believe they didn't come to this with a predetermined outcome in mind."

While the case has been pending, software developers have shifted to increasingly use open-source technologies, which could reduce the chances for a similar case in the future. Microsoft, for example, began releasing its .NET programming framework as open-source software in 2014, and Apple released its new programming language Swift as open source in 2015. Meanwhile, software companies are increasingly working together to develop open standards to ensure their products are compatible.