No, you lose the patent license, not the copyright license.

From Facebook's blog post:

> The patent grant says that if you're going to use the software we've released under it, you lose the patent license from us if you sue us for patent infringement.

https://code.facebook.com/posts/112130496157735/explaining-r...

Which one has more value? A file included in the repo, written in legalese, on which Every single source code file's copyright headers point to (and the README file as well), or an ambigous blog post?

Reading the file in its current form (https://github.com/facebook/react/blob/b8ba8c83f318b84e42933...), You lose the license to make, have made, use, sell, offer to sell, import, and otherwise transfer the [React] Software.

You lose the license granted in the PATENTS file, but you might not lose the license granted in the LICENSE file. (IANAL, so no idea whether that's true.)

Does the additional patent grant in the Facebook BSD+Patents license terminate if I create a competing product?

No.

Does the additional patent grant in the Facebook BSD+Patents license terminate if I sue Facebook for something other than patent infringement?

No.

Does the additional patent grant in the Facebook BSD+Patents license terminate if Facebook sues me for patent infringement first, and then I respond with a patent counterclaim against Facebook?

No, unless your patent counterclaim is related to Facebook's software licensed under the Facebook BSD+Patents license.

Does termination of the additional patent grant in the Facebook BSD+Patents license cause the copyright license to also terminate?

No.

From: https://code.facebook.com/pages/850928938376556

My reading must be off, then. Is "under any Necessary Claims" the magic phrase?

Yeah, it is defined at the bottom of the file:

> A "Necessary Claim" is a claim of a patent owned by Facebook that is necessarily infringed by the Software standing alone.

So when they say "license under any Necessary Claims" they are granting a patent license, the copyright license in the LICENSE file is separate.

The FAQ link provided by silentstreet makes it very clear:

> Does termination of the additional patent grant in the Facebook BSD+Patents license cause the copyright license to also terminate? > > No.

https://code.facebook.com/pages/850928938376556

https://code.facebook.com/license-faq which they published a year or so ago explicitly says you keep the BSD license.

"Does termination of the additional patent grant in the Facebook BSD+Patents license cause the copyright license to also terminate?"

"No."

Above from bottom of page to be clear to agree!

It's deeper than that.

Say you are a company A, and have product P that uses react.

You find out that company B infringed on a patent in your other product Q.

You sue B.

It turns out B is owned by FB.

Your product P is in trouble.

"If you are OK with using MIT or BSD licensed software you should be OK with using Facebook's BSD + Patents software." (From GP)

I.e. patent grant nullifies, and you are left with a BSD only license.

The main BSD license file says plainly that Facebook grants you the right to use the software. Nowhere does it say that it is merely a grant of copyrights. While the Facebook Additional Grant of Patent Rights purports to be purely additive, its mere existence changes how I would interpret the scope of that main license file. As such, I find the meaning and implications of Facebook's contract to be unclear. I would not want to depend on it, personally.

The feeling is a bit like stepping into a restaurant that offers lead-free burgers for only $0.99 extra. Theoretically, declining the upcharge is no different than eating anywhere else. Yet...

I am not a lawyer. This is not legal advice.

Because you can't just rewrite it in another framework if such a totally contrived case arrive?

The way I'm reading some related discussions, it seems their main problem is being suddenly open to patent lawsuit.