In case you were wondering--and I was, given the noises Microsoft has been making lately about the open-source operating system--Linus Torvalds does indeed own the trademark on Linux. Interestingly, so does Rosch, a detergent company based in Switzerland.How can this be? The explanation is simple. Trademarks are a little different from patents. A patent is fairly broad, and one can't copy or use something someone else has patented with permission (and, presumably, a royalty).

However, trademarks are granted on a much more narrow basis. As the Wikipedia puts it (and they're not wrong this time): "Trademark rights generally arise out of the use and/or registration of a mark in connection only with a specific type or range of products or services."

That's why a search of the United States Patent and Trademark Office's site turns up 204 trademarks (both "live" and "dead," or abandoned) related to Linux.

The list includes expected ones like LinuxWorld, which is owned by IDG Inc., the company that runs the conference, and "The Linux Foundation," which is owned by. . .The Linux Foundation.

Then there are the offbeat ones. My favorite here is serial number 78185500, abandoned in November, 2003, by one Rick Stanley Inc. of New York. It's for "Got Linux?" as a trademark for computer consulting services.

Anyway, back to the big stuff. The piece de resistance is Linus's trademark. It's serial number 74560867, registered in September, 1995, and its is for the word Linux when it's used to refer to a "computer operating system software to facilitate computer use and operation." (See below. I know the small version of the pictures look crappy. Click to enlarge them, and they look fine.)

The Rosch trademark--serial number 75735641, registered in December, 2000--covers "laundry detergents and laundry bleaches for home use; all purpose cleaning preparations; general purpose scouring powders; skin soap" and other stuff like that. This is clearly separate from and unlikely to be confused with "computer" Linux, so there's no conflict. (I wonder if a Linux detergent is free as in free or free as in beer, or whatever the heck the fanboy cliche is?)

However, there are also trademarks which appear, at least to a layperson (me) to come awfully close to what one would think Linus himself is entitled to. Take "Linux Supercomputing," which is trademarked for "Cluster computer system hardware comprising central processing units (CPUs), computer systems and servers, [etc.]" by Linux Networx Inc., of Bluffdale, Utah.

And Finite State Machines Labs Inc., of Socorro, New Mexico, owns "RTLinux" as a trademark for "computer software that adds a hard real-time capability to an open-source, general-purpose operating system."

Interestingly, both "United Linux" and "Pogo Linux" had at one time been trademarked by the companies pushing that respective distribution (here and here). However, both marks are now abandoned, so one might suspect that Linus and his attorneys are indeed keeping an eye on the trademark.

In this vein, the USPTO search also turns up a cheeky 1999 attempt by one Taiwan Branch Corp. to trademark Linux for "computer programs." It was abandoned in 2001.

After reviewing the full list for a while, one thing that struck me--from its breadth, but even more so from the number of trademarks that have been abandoned--is that most Linux trademarks aren't worth all that much. Unless you're Linus Torvalds. Or a detergent company in Switzerland.

[Update, Monday May 21, 11:40 am. 1) In the comments, below, "Alvin," makes a point about "likehood of confusion," of which I was unaware. According to Marklaw.com, he's correct: "The likelihood of confusion test is also one of several examinations conducted by the U.S. Patent and Trademark Office in determining whether to approve an applicant's trademark application." Thanks, Alvin. 2) I should have been more precise above, in that the number "204" includes all results returned when you search the USPTO trademark base for "Linux." Thus it includes all live, dead, and abandoned applications, as I stated above. Of the 204, by my count only 26 are currently "live."-AW]

P.S. Here's the full list, or screen captures, anyway. Click to enlarge and they're readable.