The idea that I can be presented with a problem, set out to logically solve it with the tools at hand, and wind up with a program that could not be legally used because someone else followed the same logical steps some years ago and filed for a patent on it is horrifying. (John Carmack)

Patents protect implementations, not ideas. But in software, implementations and ideas are the same thing, because the implementation is only an expression that communicates the idea. Software is speech.

more...