UC Berkeley law professors Jason Schultz and Jennifer Urban may have found a way to successfully shield open source developers from project-killing patent infringement law suits. The catch being that their solution requires the FOSS community to [gasp] file patents.

Schultz and Urban's solution, the Defensive Patent License, requires a group of copyright owners that dedicate their patents solely to defensive purposes. Much like GPL there is a standardized license that is distributed within the group.

Much of the DPL revolves around the honor system. Members of a DPL must submit all of their patents to the defensive patent portfolio and should a member choose to leave, he or she can't revoke the patents already submitted. Group members can use all patents within the portfolio royalty-free as long as they don't file an offensive lawsuit or withdraw any patents from the portfolio. This ties in with the biggest point of the DPL: members of a patent portfolio have to agree that the patents are being filed expressly for defensive purposes, no money is to be made off of licenses or offensive suits.

Much of the DPL is still undecided at this point and there are some key issues that haven't been fully addressed yet. More on DPL as it develops.