Location: Politecnico di Milano, Room S01, Piazza Leonardo da Vinci, 32, 20133, Milano, Italy. Richard Stallman will explain how software patents obstruct software development. Software patents are patents that cover software ideas. They restrict the development of software, so that every design decision brings a risk of getting sued. Patents in other fields restrict factories, but software patents restrict every computer user. Economic research shows that they even retard progress. This speech will be accessible to all audiences and the public is encouraged to attend. (There is a subscription fee for people who are not AICA associate members.)