"Microsoft understands that GPL is a marketing scheme aimed right at their heart. First, GPL code will always result in a far earlier implementation of a new software idea to hit the market. Second, it `scorches the earth' because once the implementation exists, it kills competitive development that's based on a proprietary model. The situation has already done lots of damage to proprietary software patents. GPL makes it extremely easy to do prior art searches. As a result, patent challengers are having an easier and easier time getting patents invalidated. While this is overall a good situation for the software market, it can be damaging to a single software company that was planning on using a software patent on something obvious to get a lot of money."