Red Hat fired back at a patent challenge using their contributions to open source as the basis for their suit. It’s a novel approach for commercial companies who have made some of their software open source, but still own the copyright. In this case, Red Hat charges that some of their software released under a GPL2 license was included in the proprietary software from Twin Peaks Software, a company which has launched a patent infringement case against Redhat. There are a couple of points to take from this. First, by releasing code as open source, you don’t necessarily give up ownership, meaning your IP rights are still yours. Second, in this case I suspect Red Hat will get some support from open source advocates both for their original contribution as well as for defending the open source license they used. Finally, companies considering filing a software IP lawsuit, need to be sure that they know what’s in their code before they push the button.