20 years is too long
Patents last for at least 20 years. This term has been set by TRIPS (art 33).
Patents exist to encourage researchers to publish their ideas. The researcher gets a temporary monopoly, and in return, society gets access to the idea when the patent expires.
In software, if you have to avoid using ideas from the past 20 years, your software will be useless. (See: Use software from 20 years ago)
Similarly, it doesn't take 20 years to figure out how a software package works, so the disclosure with a 20 year delay on your freedom to use the idea, is a pointless deal. (See: The disclosure is useless)
Related pages on ESP Wiki
- Slow process creates uncertainty
- Invalidating harmful patents#Takes_years - the courts system is too slow to work for software developers
- Use software and functionality from 20 years ago
- Utility models and innovation patents - which have a term of less than 20 years
- An Open Letter From Jeff Bezos On The Subject Of Patents, (2001? or earlier), Jeff Bezos of Amazon suggests a 3-5 year term for software patents