I must admit that I just came across the Open Invention Network (OIN). This is a company created last year by IBM, Novell, Philips, Red Hat, and Sony. Its purpose is to act as a patent pool which will accumulate a number of software patents that will be cross-licensed to the members. The patents will also be "available on a royalty-free basis to any company, institution or individual that agrees not to assert its patents against the Linux operating system or certain Linux-related applications." OIN has acquired a good number of patents, including a valuable batch of e-commerce XML patents from Novell.
This is an impressive initiative that makes Linux and open source more secure against costly patent litigation. The software patent environment is increasingly looking like the Cold War, with companies accumulating patents as a deterrent from attack. OIN is just another weapon that ensures that the open source patent environment is in a state of Mutually Assured Destruction (MAD). The first to shoot will be likely to unleash the mother of all patent litigations.