In response to

This seems a very bad caricature of the open source view. The way I understand it is that the ideas behind the software can be patented rather than just the software itself. So, for example, you come up with a means for managing some resource that is very efficient and write some software to do it, no-one else can use that idea without paying you, even if they implement it completely differently and do a much better job.

There are a whole ruck of ideas (linked lists, relational databases, hashed indexes for example) that are fundamental to working in a modern IT infrastructure. Where would Oracle (or MySQL) be if IBM had fought a patent over SQL – it could never have become the standard it is. How would this make the world a better place?

We cannot identify what ideas around today are as fundamental for the next wave of technology. It is totally naive to support patenting things like algorithms and good ideas. Profit comes from being better and quicker than your competitors. Profit is at the edge of things, where you are ahead of your competition, where you use sharper and better tools than they do.