The patent difference between software and other technologies

I think software patents should not be allowed. The big difference between software and other technologies is that it consists of extremely many ideas, and almost none of these has any significant development cost that needs to be recovered.

I can see the necessity of patents in industries where you need to invest millions of dollars to create new ideas, which could then easily copied by other companies. For instance if medical drugs could not get patented for a while, nobody might go through the immensely expensive processes of developing new drugs. In software, however, it is a rare exception that generating a single innovative idea here is very expensive, so patents are not necessary to ensure innovation. The value of software lies in the well executed composition of elements, which is not patentable, anyway - the appropriate way to protect software investments are copyright laws.

So the primary business case for software patents is to go after competitors, which is not good for competition and a serious latent threat to innovative small businesses who do not have the ressources to check for every small detail whether someone snatched a patent one needs to work around. If, on the other hand, a small business tries a patent fight against a large corporation, it has a slim chance since it is bound to infringe on some of the "defensive" trivial patents held by the large corporation.

This comment on serverside about the new zealand legislation banning software patents has also a very good argumentation.

My conclusion: I think there is a good case that patents seriously hamper technological progress.