What constitutes unfair copying? This question comes up again and again in debates related to a variety of industries, and the software space is no exception. But, interestingly, a recent lawsuit involving tech giants Google (News - Alert) and Oracle focused on application programming interfaces, which need to have some commonality with the software programs with which they interface to work, making the whole debate a bit hairier.

Here’s the story.

Several years ago Google wanted Java-based programs to run on its Android operating system. It talked with Java creator Sun Microsystems (News - Alert) about how they could work together to make that happen, but as Vox Technology recently reported, those talks broke down. So Google went ahead and built APIs that didn’t reuse Java code, but did leverage some of the same names and functionality found in Java software.

Oracle (News - Alert), which later bought Sun Microsystems, sued Google in 2010 over the APIs. U.S. District Judge William Alsup in 2012 ruled that APIs can’t be copyrighted; however, that opinion was overturned on appeal.

But the fight raged on.

Following a two-week trial this summer, a federal jury unanimously ruled that Google’s Android (News - Alert) OS does not infringe on Oracle-owned copyrights because its reimplementation of 37 Java APIs is protected by fair use. Oracle, which may have asked for as much as $9 billion had it won the lawsuit, said it plans to appeal.

This fair use conclusion was backed up by Google’s references during the trial of a 1995 ruling concluding that Borland didn’t not infringe on copyright in creating a spreadsheet program with menus organizations like those in Lotus 1-2-3.

Recent reporting by Vox Technology added to that by noting the “long tradition of computer programs being designed to be compatible with other programs created by third parties.” Open source project Samba, which allows Linux users to share files with Windows users, is one such example and is widely accepted as legal, according to the report.

The ruling in Google’s favor is viewed as a win for software developers, according to several sources.

“Google’s win somewhat softens the blow to software developers who previously thought programming language APIs were free to use,” reported Arstechnica. “It’s still the case that APIs can be protected by copyright under the law of at least one appeals court. However, the first high-profile attempt to control APIs with copyright law has now been stymied by a fair use defense.”

IDC (News - Alert) analyst Al Hilwa agreed, but noted that this ruling sets a high bar for creativity before deserving protection from fair use.

“APIs are used pervasively in software for interoperability, and so most developers would likely prefer not to be burdened by copyrights around APIs,” Hilwa added. “Also, when you look at the shift that is taking place toward open source, you can say that the licensing of copyrights overall, in the world of developer platforms and tools, has trended toward more permissive licensing. Still many companies and developers want to be free to protect their creativity in any manner they wish. I think this is a situation where Oracle feels deeply that it has been wronged and has pursued every approach possible to get remedy. I think protection through APIs was not their first choice in seeking remedy.”