Algorithms Should Not Be Patented

I remain convinced that the patent policy most fair and most suitable for the world will regard mathematical ideas (such as algorithms) to be not subject to proprietary patent rights. For example, it would be terrible if somebody were to have a patent on an integer, like say 1009, so that nobody would be able to use that number “with further technical effect” without paying for a license. Although many software patents have unfortunately already been granted in the past, I hope that this practice will not continue in future.

Donald Knuth’s letter to the European Patent Office, April 2009