Google has joined the fight to save Linux from an army of patent-waving Microsoft lawyers.

With Redmond threatening to collect royalties from Linux users and distributors across the industry, claiming that the open-source operating system violates 235 of its patents, Google has thrown its considerable weight behind the Open Invention Network (OIN), a consortium of companies bent on protecting open-source software from legal attack.

All OIN members - including big names such as IBM, NEC, Novell, Philips, Red Hat, and Sony, as well as Google - agree not to use their Linux-related patents against each other, and all have free access to a collection of additional open-source-related patents purchased by the consortium as a whole.

"Patent issues...become a much smaller concern inside the community, and OIN members can focus their energy on writing and releasing software rather than vetting their code for intellectual property issues," wrote Google open source programs manager Chris DiBona on The Official Google Blog. "It's the legal equivalent of taking a long, deep breath."

As more names join the OIN, pooling more and more Linux-related patents, it becomes increasingly difficult for a company like Microsoft launch an attack on the OS. "We are very open about our patents," OIN chief executive officer Jerry Rosenthal told The Reg. "We list them on our website, so that people who might want to do Linux harm understand why it would not be in their interest to bring litigation."

Knowing they're protected by the OIN, Google's DiBona argues, open source developers are more likely to drive the industry forward: "We believe Linux innovation moves fastest when developers can share their knowledge with full peace of mind. We're proud to participate in an organization that's making that possible, and we look forward to seeing OIN grow and thrive."

Google is OIN's first "end-user licensee," which means it's the only member who doesn't sell, distribute, or develop Linux code. It only uses the OS within the company.

"Google is such a well-recognized and well-thought-of name, we'll now see other end-users become licensees," said Rosenthal. "We want to continue to grow this ecosystem of patents, so that ultimately a vast majority of [Linux-related] patents will be available to the community for free."

According to DiBona, Google's in-house open-source gurus are fond of saying "Every time you use Google, you're using Linux...Check a Google engineer's workstation, and you'll probably find it's running Linux," he explained. "Do a search on Google.com, and a Linux server will return your results. Ever since Google got its start, Linux has given us the power and flexibility we need to serve millions of users around the world."

That puts the company squarely in the sights of Microsoft general counsel Brad Smith and licensing chief Horacio Gutierrez, who recently told Fortune that Redmond plans to use 235 of its OS patents to collect royalties from Linux users and distributors alike.

To date, the OIN has purchased more than 100 worldwide patents and patent applications involving Linux - and that doesn't include the patents individually owned by its members. The difference, Rosenthal says, is that unlike Microsoft, the OIN is completely open about its patents and uses them strictly for defensive purposes. "Microsoft says they have 200 some Linux patents, but they won't tell us what they are," he told us. "That's just an attempt to spread fear, uncertainty, and doubt. It they tell us what the patents are, then we can deal with it, but they won't. It makes you wonder they really have." ®