If you expected to read a story someday about a new patent-infringement suit against Linux, this is it. But, while neither of the plaintiffs in this lawsuit is named Microsoft, at least one technology law blog is suggesting the Redmond, Washington-based software giant might be involved.

Several news outlets are reporting that IP Innovation LLC and Technology Licensing Corp. have sued Red Hat and Novell in the U.S. District Court for the Eastern District of Texas, claiming patent infringement from such products as the Red Hat Linux system and Novell's SUSE Linux Enterprise Desktop and SUSE Linux Enterprise Server. The plaintiffs are seeking an injunction and damages, and have alleged that, because Red Hat and Novell had notice of the patents, their infringement is willful.

The suing companies cited U.S. patents No. 5,072,412, No. 5,394,521, and No. 5,533,183. The patents, issued in 1991, 1995, and 1996 are all entitled User Interface with Multiple Workspaces for Sharing Display System Objects.

None Mention Linux

None of the three patents mention Linux or operating systems at all. Instead, they describe the interaction between a data-processing system and a user interface.

"The present invention," reads one of them, "relates to the user interface of a data-processing system" and to the "organization of display objects such as windows into groups which are displayed together on a display-based user interface, each group being appropriate to a particular user task."

Many observers have expected to hear of Microsoft -- instead of these relatively unknown companies -- initiating a patent suit against Linux. Microsoft officials have said that the open-source OS violates as many as 235 of its patents, but so far the company has taken no direct legal action.

Microsoft has, however, signed cross-licensing deals with LG Electronics, Samsung, Xandros, Novell, and others, in which it promised not to hold those companies' customers liable for Linux infringements.

Where's Microsoft?

One law-oriented technology site, Groklaw, is suggesting that Microsoft might have a surreptitious hand in this lawsuit. In looking at the companies behind the suit, the blog said in a posting last week, it's time to play "where's Microsoft?"

First, it mentions that Microsoft CEO Steve Ballmer recently said in a speech that companies other than Microsoft might want Red Hat and others to pay for patent infringement. "Is he a prophet or merely well informed?" the blog asked.

Then, it quotes other research that Illinois-based IP Innovation is a subsidiary of California-based Acacia Technologies Group, which, in July, announced that Jonathan Traub, former Microsoft Director of Strategic Alliances for Mobile and Embedded Devices, was joining the company as a vice president.

Earlier this month, Acacia said that Brad Brunell was coming aboard as senior vice preisdent. Brunell is the former manager of intellectual property licensing at Microsoft. In fairness, Groklaw did note that Acacia, which is in the business of licensing and lawsuits, also has sued Microsoft.