... Smith was having Microsoft's lawyers figure out how many of its patents were being infringed by free and open-source software. Gutierrez refuses to identify specific patents or explain how they're being infringed, lest FOSS advocates start filing challenges to them.

But he does break down the total number allegedly violated - 235 - into categories. He says that the Linux kernel - the deepest layer of the free operating system, which interacts most directly with the computer hardware - violates 42 Microsoft patents. The Linux graphical user interfaces - essentially, the way design elements like menus and toolbars are set up - run afoul of another 65, he claims. The Open Office suite of programs, which is analogous to Microsoft Office, infringes 45 more. E-mail programs infringe 15, while other assorted FOSS programs allegedly transgress 68.

Now that Microsoft had identified the infringements, it could try to seek royalties. But from whom? FOSS isn't made by a company but by a loose-knit community of hundreds of individuals and companies. One possibility was to approach the big commercial Linux distributors like Red Hat and Novell that give away the software but sell subscription support services. However, distributors were prohibited from paying patent royalties by something whose very existence may surprise many readers: FOSS's own licensing terms.