Software patents, and how to route around them

Microsoft recently used its patents on some aspects of the FAT filesystem to beat TomTom into submission, with the latter ending up having to change its products, pay Microsoft and license some of its own patents to it. It wasn't a good result for TomTom, even though there were signs of Microsoft being careful in its approach to the GPL.

The other sad thing about the settlement was that the validity of Microsoft's patents were never tested in court. The ideal end to the software patent wars would be for most of them to be thrown out, but that will take time and resources. Patent pools are a good way of coming together to stand up to bullies, they don't solve the general problem. Until the law intervenes, we need to find technical ways around software patents.

Now Andrew Tridgell, a developer working on Samba has posted a patch that retains most of the functionality of the FAT implementation, while removing the functionality that infringes the patent used against TomTom. The price paid is that short filenames aren't generated when an application writes a file with a long filename. This breaks backward compatibility with applications that can only read 8.3 filenames, but if you're sticking to Free software, that's a very small number indeed.

That a patent is bypassed so easily by so small a technical measure should give you an idea of how much merit the patent really has, but as I've said it needs to be tested in court for the threat to go away. Until then, reactions like this from the Free software community are our best weapons.