Richard Stallman’s latest article on software patents suggests that instead of a law excluding software from patentability, we need a law saying “that developing, distributing, or running a program on generally used computing hardware does not constitute patent infringement.“
This would achieve the same goal as a software exception but avoids the difficult problem of drafting a text which classifies patents as “software” or “non-software”.
For an example of how this is workable, he refers to 35 U.S.C. Section 287 (c), which was written in 1996 to shield surgeons from patent risks.
If you have ideas for how this could work best, please feel free to write them on the relevant wiki page: