> If you publish this under patent grant, why did you patent it in the first place?
It could be part of a defensive patent strategy. If they successfully received a patent for that, then it makes it that much harder for a malicious third party to troll them. And if you ask me, turning around and publishing the patent under the APL demonstrates good faith to the /libre/ software community (it's a GPLv3-compatible license, no less), so that's a strategic win, too.
Wow, this is an interesting strategy. To summarize, just to make sure I got this right:
1. They make use the patent protection clauses via APL (and also GPLv3)
2. They use to to protect it from their own patent
What's still unclear to me: Does it affect other implementations? Assume that Clang/LLVM wants to implement "syntax trivia". Will they have to use exactly their implementation, and thus have to switch from their BSD-style license to APL or (A)GPL?
Not meant to be snippy, but ...
If you publish this under patent grant, why did you patent it in the first place?
Apart from that, I must say that I'm very glad to live in a jurisdiction where these types of patents are void. I could have written down this idea long before 2011, but I never thought this would be worth patenting. (Don't get me wrong, the concept is really great, but to me it doesn't make any sense to prevent others from implementing the same idea. It's not like Microsoft had to invest thousands of dollar into research to develop this idea, and aims to refinance that development effort via patent licenses.)