Z:gnu-www-ja-danger-of-software-patents--c052f4-For instance, I saw a patent f/en

For instance, I saw a patent for something like the fast Fourier transform, but it ran twice as fast. Well, if the ordinary FFT is fast enough for your application then that's an easy way to avoid this other one. And most of the time that would work. Once in a while you might be trying to do something where it runs doing FFT all the time, and it's just barely fast enough using the faster algorithm. And then you can't avoid it, although maybe you could wait a couple of years for a faster computer. But that's going to be rare. Most of the time that patent will to be easy to avoid.