Sometimes, it seems as if lawsuits are as inseparable from the open source ecosystem as unshaven, geeky developers. In the past, Linux has even had to defend its very name in the courts. But open source advocates have a good record of winning such cases, and they chalked up another important victory last week in a fight that pit Red Hat (NYSE: RHT) and Rackspace (NYSE: RAX) against a foe with a long history of litigation against technology giants.

The lawsuit dates to last June, when Uniloc USA alleged in federal court that Rackspace had violated a patent involving the processing of floating point numbers—specifically (for those of you keeping track at home), U.S. Patent 5,892,697. Red Hat, which supplies the Linux operating system that comprises a core component of Rackspace's cloud computing platform, provided the defense for Rackspace as part of its Open Source Assurance program.

The case didn't last long. Chief Judge Leonard Davis dismissed it on the grounds that mathematical algorithms are unpatenatable. The decision was announced March 28.

Both companies have celebrated the decision as an important win for the open source ecosystem against "patent trolls." According to Michael Cunningham, executive vice president and general counsel for Red Hat, "This is a major victory for open source software ... the thoughtful dismissal by Chief Judge Davis on a 12(b)(6) motion will encourage earlier decisions by other courts on invalid software patents, reducing vexatious litigation by non-producing entities and their corrosive effect on innovation."

Cunningham's counterpart at Rackspace, General Counsel Alan Schoenbaum, expressed his satisfaction at "defeating this patent troll. We hope that many more of these spurious software patent lawsuits will be dismissed on similar grounds."

Litigious tendencies are not unique to the open source world, of course—and indeed, Unilogic in the past has brought similar cases against a variety of companies that deal primarily in proprietary software, including Adobe, Microsoft, Sony and Symantec.

But the stakes for open source vendors tend to be different.  For one, since the code of many of their products is publicly available, it can be easier to scour their work to find litigation opportunities. More importantly, though, many open source companies lack the legal and financial resources to defend themselves vigorously in long patent cases. In that sense, the successful collaboration between Red Hat and Rackspace is a reminder that open source vendors which might seem easy prey have access to support from channel partners who have a strong interest in preventing patent trolling in all parts of the ecosystem.

And last but not least, this victory is also a reassurance, however small, that open source is indeed safe to deploy within integrated software platforms. This might seem like something that organizations shouldn't even have to consider anymore—the 1990s, after all, have come and gone—but in an era when talk of "total cost of ownership" (TCO) and frivilous litigation predominate, it's worth keeping in mind.