React has a non-open license: https://github.com/facebook/react/blob/master/PATENTS, which basically says that an organization can no longer use React once it sues Facebook for any (unrelated) patent infringement.
This is an automatic no-way for React for any major company
To be clear: only the patent license ceases, which is something you wouldn't even get in the first place with most other licenses. It may also be that no patents are used in React at all. I personally do not know of any that are. (Disclaimer: Not a lawyer, not speaking on behalf of FB, just my own reading of the language.)
Yes... I'm really surprised that people aren't talking about this more seriously. They have removed the worst of it, but it still looks like it gives Facebook an advantage in any patent conflicts with any company that uses React, Immutable, Hack, HHVM, GraphQL, etc. anywhere in the dependencies. It appears that the PATENTS file claims that if Facebook infringes on your patents, you can't defend your patents without a risk of immediately losing the ability to use React (or other Facebook library). Maybe a lawyer would be able to make more sense of that PATENTS file.
I'm surprised that Apple might be using React, since they have had big patent battles with Facebook:
I've heard that Google doesn't use React, but I don't know how long companies will be able to do that as Facebook libraries increasingly become dependencies of other libraries.
I don't have links to any; they might be all internal. The current iteration of the patent grant was developed in collaboration with Google to meet their needs, so if there is any complaint they still have with it, that is news to me.
Only public evidence I have of this is Firebase (owned by Google) being unwilling to use React and then happy with the new license:
I would like to find out more specific information. It seems like the section of the license below says that you can never make any patent claim against Facebook or you lose rights to use the software. Doesn't that mean that Google could never initiate patent claims against Facebook, while Facebook could still initiate patent claims against Google? It seems strange that Google (or Apple) would do that. I am not a lawyer though, and the PATENTS file may not mean that.
> The license granted hereunder will terminate, automatically and without notice,
if you (or any of your subsidiaries, corporate affiliates or agents) initiate
directly or indirectly, or take a direct financial interest in, any Patent
Assertion: (i) against Facebook or any of its subsidiaries or corporate
affiliates, (ii) against any party if such Patent Assertion arises in whole or
in part from any software, technology, product or service of Facebook or any of
its subsidiaries or corporate affiliates, or (iii) against any party relating
to the Software.
"The Virtual DOM, among React's most compelling features, has also seen its core ideas filter into other framework projects. But more importantly, React is licensed with what I believe to be a potentially unacceptable patent clause, which states that an organization can no longer use React once it sues Facebook for any (unrelated) patent infringement. This has already generated some concerted pushback from both WordPress's Calypso and React contributors."
[1] https://code.facebook.com/posts/1639473982937255/updating-ou... [2] https://news.ycombinator.com/item?id=9356508