Comment by brundolf

Yes, that's how patents work. I believe patents normally expire ~20 years after being filed. The idea is to incentivize people/companies to invest the resources in solving really hard problems, knowing they'll be able to make back their investment in the time before it expires (at which point everyone can then use it)

Software patents are controversial because of the rate things move in software; a software discovery from 20 years ago is likely worthless by the time the patent expires. I think the window should be shorter for software (5 years? 3 years?), just enough to make back the investment but not milk it until it's dead

But as they go, this kind of real problem-solving is one of the more defensible kinds of software patents imo. Many software patents out there are things like "do X but store it in a database", which is obviously nonsense