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."