Experts cast doubt on Microsoft's patent claims

…but he too said Microsoft needs to take the initiative in describing what patents Alfresco might be violating. "Until we know — and IBM knows and Red Hat knows — what can we do?"

Microsoft wouldn't say whether it believes any of its products infringe patents held by other companies with which it doesn't have a licensing agreement. It also wouldn't say whether it requires its own programmers to check if their software infringes others' patents, whether the company routinely checks to see if its products infringe or whether it ensures its products don't infringe before shipping them.

Horatio Gutierrez, Microsoft's vice president of licensing, said in an interview that the alleged open-source infringement is "not accidental". As evidence that the infringement is intentional, the company points to a 2006 speech by Richard Stallman, who single-handedly built much of the intellectual and legal framework of the free and open-source software movements.

By sitting in my chair right now I'm probably violating somebody's patent

Matt Asay, Alfresco

Stallman didn't come close to a detailed analysis of where problems might lie or even a definitive admission, though. In his speech, Stallman refers to a 2004 study funded by Open Source Risk Management, a start-up selling insurance in open-source intellectual-property matters. "Two years ago, a thorough study found that the kernel Linux infringed 283 different software patents, and that's just in the US. Of course, by now the number is probably different and might be higher," Stallman said.

The quality factor
There's a wide gap between being accused of infringing a patent and being found in a civil lawsuit to actually infringe. And a recent Supreme Court decision means the gap is likely to be getting wider.

In a unanimous April decision, the court sought to set a higher standard for weeding out patents for obvious technology. "Granting patent protection to advances that would occur in the ordinary course without real innovation retards progress and may, in the case of patents combining previously known elements, deprive prior inventions of their value or utility," the court said in its opinion, a decision that could make it easier to challenge patents' validity or harder to obtain them in the first place.

Microsoft believes its patents are solid. "Our patent portfolio scores very high on patent quality and science linkage," the company said, pointing to its second-place ranking among computing companies by the Patent Board, a patent analysis firm.

The court's decision was welcome news to those who complain about the quality of software patents. Improving patent quality to ensure patents are "truly novel, truly not obvious and truly useful" is one major part of the CCIA's patent reform agenda.

Mike Dillon, Sun's top lawyer, said his company was "hit with two new patent troll cases" in April but is cautiously optimistic about the effects of the Supreme Court's move. He called spurious patent suits a "tax on innovation".

Those sentiments were echoed by Dillon's colleague, Sun chief technology officer Greg Papadopoulos. "Are software patents useful? My answer is mostly 'no'. Copyright appears to be mostly better for maximising innovation while giving individual copyright holders the ability to modulate compensation and derived works."

Torvalds was more direct. "The bulk of all patents are crap," he said. "Spending time reading them is stupid. It's up to the patent owner to do so, and to enforce them."