id Software’s highly anticipated game Doom 3 uses a graphics technique for rendering stencil shadows called “Carmack’s reverse”, named after its author and id Software’s rockstar head developer, John Carmack.
Apparently this did not stop Creative Labs, noted makers of the SoundBlaster soundcards, from quietly patenting Carmack’s algorithm with the USPTO in October 1999. This recently came to a head when HardOCP noted an awkwardly-written Creative/id Software press release that spoke of a cross-licensing deal. The jist of the story was this: Creative lets id Software use their own algorithm without getting sued, and id Software agrees to use Creative’s EAX HD audio in subsequent games.
There may also be some prior art, with nVidia’s Sim Dietrich pointing out he publicly described a similar technique earlier in 1999 (at a Creative developers forum, no less). Creative asserts they invented it first. Not like it matters – launching a legal defence requires lawyers, and lawyers cost a lot of money. Carmack chose the path of least resistance, although he told Beyond3D he’s not exactly super-happy about the whole thing.
Even the open source community, afraid of having to face future litigation from companies snatching up patents on common coding techniques, have urged FLOSS developers to fight fire with fire, and preemptively patent everything they write.
Ex-patent lawyer and EFF staff attorney Jason Schultz opines that such patents get through the system due to a staggering backlog, although this doesn’t answer the ugly question: should you be able to patent software? Software patents are valid in the USA and Japan, and is currently being considered by the EU.
Do software patents stifle or promote innovation? I’m not qualified to answer that, but I do notice that Creative just got a sweet deal with minimal exertion on their part.