The first ever Linux patent-infringement suit was brought by a "portfolio licensing" company called IP Innovation, last Tuesday, over a patent that was once owned by Xerox.
IP Innovation LLC filed the claim, in Texas, that Linux operating systems from both Red Hat and Novell have infringed US patent number 5,072,412 for a "User interface with multiple workspaces for sharing display system objects" that was filed in 1987 by Xerox and granted in 1991. Both companies were warned of the likely suit, so their actions are "deliberate and wilful", says IP Innovation.
The timing of IP Innovation's attack on Linux has attracted some attention, after the last company to threaten legal action against suppliers of the open-source operating system, SCO, was delisted from the Nasdaq.
"I think SCO II has arrived," said open-source commentator Groklaw, referring to the SCO's bid to sue Novell and IBM over copyright in their Linux distributions.
Commentators have claimed that the IP Innovation's patent is a weak one that is likely to be demolished by a demonstration of prior art. It is also claimed that while Microsoft has declined to sue over its own claimed Linux patents so far, IP Innovation may be testing the patent waters on its behalf.
The patent's description "is so replete and generic that it could apply to a wide array of visual tools," said Beta News in April when Apple was sued under the same patent. Although windowing technology was far advanced by that time, the patent was apparently based on work to allow Xerox's Star workstations, developed in the 1980s, to collect multiple workspaces under a row of tabs.
IP Innovation LLC is a subsidiary of a company called Acacia whose "primary corporate mission is to file patent lawsuits" according to the Patent Troll Tracker blog. And Acacia has taken on a couple of former Microsoft employees in recent months, including Brad Brunell, who was general manager of intellectual property licensing at Microsoft until he joined IP Innovation on 1 October -- just eight days before the suit was filed.
Like other software patents, this one is less likely to have any effect outside the US, but the case will be an interesting test of the open-source community's ability to innovate around patents and other restrictions, according to Andrew Katz, a solicitor at Moorcrofts, a UK-based firm specialising in technology law.
The open-source community has often claimed that any patent infringement can be quickly removed by collective efforts to rewrite parts of any program, leaving the patent holder with only retrospective damages. This may not always be so easy, warns Katz. "It may be possible to alter software transparently," he said. "If the patent is fundamental, designing around it might remove some functionality."
Just to make it clear, this suit has nothing to do with Linux the kernel.