Actually I see it as

3. You can't sue Facebook because your app is similar to Instagram

Ok, so expanding on that, the problem becomes this:

1) You create a successful app using React

2) Facebook blatantly copies your app.

3) You can't sue Facebook

Is such a clause actually enforceable? Has this been tested in a court of law? Just curious.

Well, the clause isn't "you can't sue", it's "you have to stop using React if you sue".

But what if you don't stop using it?

You can be sued by Facebook for infringing their license.

Which brings us back to my original question ;)

I am not a lawyer, but "not bringing a patent infringement lawsuit against Facebook or its affiliates" suggest that anyone using React can't file a lawsuit against Facebook over patents and NOT vice versa as you suggest.

Can you point which part of the license says what you claim? Thanks

In their PATENTS file: https://github.com/facebook/react/blob/master/PATENTS#L14-L2...

If you read it, it doesn't seem like GP's claim is completely true.

Are you talking about this part?

> if Facebook or any of its subsidiaries or corporate affiliates files a lawsuit alleging patent infringement against you in the first instance, and you respond by filing a patent infringement counterclaim in that lawsuit against that party that is unrelated to the Software, the license granted hereunder will not terminate under section (i) of this paragraph due to such counterclaim

And, please, point in which part of the file you linked where is said that your license is terminated if Facebook sues you

[edit] ugh, meant to put this elsewhere, rough morning.

> 3. Facebook sues you and takes all your reacts and reducers

Perhaps I highlighted that part because the original OP talked about Facebook suing you first. Dude.

No, this is a complete misunderstanding of the license.

Please read Facebook's official FAQ on this matter::

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

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

>No.

Yes it would totally make sense for facebook to effectively kill react (wasting millions of their paid engineering hours) and forever taint their developer community by using that clause to sue another company just because they compete. </sarcasm>

Hypothetically if you ever grow so big and frighten facebook to that degree, migrating off react would be an easy problem to solve.

Hypothetically, when you're found to infringe a patent for a product that was already deployed, then the damage was already done and migrating at that point won't save you ;-)

Right but this clause assumes you are the one suing facebook for patent infringement and unless your patent is along the lines of "we use react.js to do x", then you probably have the flexibility to port it to a different framework.

BILLIONS, TRILLIONS of hours went into react /s Or maybe whole eternity... Why restrict yourself to just millions.