A conference on software patents and free software

> The DPL would promote the defensive use of software patents in a way which
> reinforces the free software community's norms; it is meant to be similar
> in spirit to the GPL. A company which buys into the DPL will put all of
> its patents under that license. Any other DPL licensee could then
> automatically obtain a royalty-free license for any of those patents

To stretch the "patent cold war" metaphor, that sounds like mutual nuclear disarmament. :)

Seems similar to the OIN, but instead of joining an organization, you just announce a license? Are there any other significant differences?