I had always understood patents to be about the mechanism of the device, not it’s effect. E.g., a particular mouse trap design, not the idea of catching mice.
But what do I know? Squeak blogger Torsten turned me on to this article about some courtroom pirates suing Apple over the User Interface in their latest operating system release. The original patent was for an old Xerox UI implemented in Interlisp-D, and now owned by a holding company.
Apple’s Tiger operating system isn’t implemented in Lisp. Do you suppose the lawyers are basing their argument on Greenspun’s Tenth Rule?