IANAL. Seriously, IANAL. The language limits itself to cases where a patent is necessarily infringed by combining the contribution with the product. The scenar

IANAL. Seriously, IANAL. The language limits itself to cases where a patent is necessarily infringed by combining the contribution with the product. The scenario in the guy's PDF (also--PDF?) is that an infringement is created later that has nothing to do with his contribution. Also, as others said, 1) if Apache wrote the agreement and says that others' future contributions can't give them a license to other patents, and indications are that people rely on that interpretation, it doesn't seem like a court would read it otherwise, and 2) generally, courts aren't dumb, and they're going to look at the purpose and context of the agreement and realize this is essentially about ensuring you can't taint a project with your invention and then sue for patent infringement, and avoid reading in broader meanings. Going a little further, maybe too far, the paragraph is in the present tense--"you hereby grant," etc. Nothing in there about your future work like you might find in, say, the IP part of an employment contract. Given that, I have a hard time seeing how your contribution in Sep 2013 binds you to license an idea that, since it didn't exist yet and nobody talked about future inventions, neither you nor the other party could've been contemplating. (On the other hand, if there was an idea embodied in your Sep 2013 contribution that merely wasn't patented or assigned to you yet, both parties could have been considering potential patents of the idea when reading the language. So Apache's answer A2 is justifiable.) Finally, I have little sympathy with people's desires to be able to enforce patents against open-source projects anyway, so yeah. While the language is friendly enough to patentholders, I almost wish it weren't. :)