UPDATE 22 Sep, 2017

"Relicensing React, Jest, Flow, and Immutable.js" (MIT license, PATENT file removed)


First, I'm not asking about the actual open source license, the situation is clear enough there. It is about an additional component about patents. It is about Facebook's open source project "react" (but actually all their open source projects, they all share that same "patent text").

You can find license and "patent clause" here (file names LICENSE and PATENTS): https://github.com/facebook/react/ - the important one being PATENTS.

This has already been discussed very thoroughly in many forums and blog posts, for example

I have read many of those discussions, but I have two questions that were not answered there. The first one ist just a confirmation of my understanding of a situation that the majority of those who posted in discussions don't face:

  1. Is my interpretation of how this may apply in my situation seems correct?
  2. How does that compare to open source projects without a patent clause?

To 1) (less important, just confirmation)

While the majority opinion seems to be "it does not matter" I think it does matter to some companies. I for example work for a startup that relies on patents (not on software itself but on methods/algorithms, like the MPEG4 patents).

If I interpret this correctly, if we use any of Facebook's open source projects Facebook can violate our patents pretty much with impunity: If we try to sue them we lose the right to patents covering their open source projects. So basically we cannot use their stuff.

To 2) (my main question)

I have read opinions that other open source projects that don't have such a clause, for example those from Microsoft or Google, nevertheless have the exact same problem, only that it isn't explicitly stated. Is that true? Is my situation not any better when I only use open source projects without such a clause?

EDIT: A recent anecdote: WordPress to ditch React library over Facebook patent clause risk. I hadn't known that "the patent clause ... was recently added to the Apache Software Foundation’s (ASF) list of disallowed licenses". Quite a few interesting links in that article too.

Another issue was raised in a comment: If you use React in a product, commercial or free, and you lose permission because of a dispute, how does that affect your users? Will they have to stop using your product now too?

  • 1
    This question is now linked from this HN thread: Facebook React.js License
    – icc97
    Oct 12, 2016 at 16:53
  • 1
    There is a facebook licence FAQ also linked from that thread: code.facebook.com/license-faq
    – icc97
    Oct 12, 2016 at 16:55
  • 3
    @icc97 The FAQ don't answer either of the two questions. The FAQ are not made for that scenario I describe, when it is I who has patents - and that can be any patent, for anything - and it is I who wants to defend my patent if Facebook uses it without agreement. Again, it can be any patent my company holds, does not have to be a (despicable) "software patent". The question is, does Facebook grant itself the right to use any of my patents and I can't do anything about it if I use there open source projects? How are other OS projects different if they have no explicit patent clause?
    – Mörre
    Oct 12, 2016 at 17:46
  • 1
    Indeed they don't - which is why I didn't add it as an answer. They seem relevant to the discussion though as the people writing that FAQ could answer your question.
    – icc97
    Oct 12, 2016 at 20:23
  • This post is very broad, including at least three distinct questions, and broadened further by your edit. Your questions lack clarity as a result. Please ask each unique question in a separate post. Sep 17, 2017 at 7:50

1 Answer 1



To understand the language used by facebook in this instance, you need to consider three things: crowd-sourcing, marketing, and vested interest. Each of these topics is extremely broad, so I'll just briefly introduce them.

Crowd-sourcing: open source communities can be advantageous to companies that leverage their work, since this reduces corporate overhead to maintain and develop content. The open source world is growing quickly, and companies want to cash in on the free value of existing content, and especially on the open-source talent pool. Some examples are: RHEL partnering with CentOS, and Campaign Chain, or various other commercial projects that are happy to leverage the open source community.

Marketing: being well-liked in the open-source world probably bodes well for the public image of private companies, especially when the private company has specialized tools. You included a link titled “Why I’m not a React Native Developer”. That’s the sentiment that companies like Facebook need to quash if they want to get people on board with their technologies, in hopes that they will rise to the top of the stack (pun intended).

Vested interests (i.e. greed): unlike the open source community, companies are possessive of every resource, including spent ones. They want to see the highest possible return on investment. Don’t be fooled, many corporations (especially ones with publicly traded stocks) have no Stallman ethic, no matter how fashionable the appearance of one may be at the moment (see above).

Answer to question 1

Sort-of. It’s not free software. The open-source initiative (sponsored in part by Facebook) has not given approval to the React license. Licenses that contain non-compete clauses aren’t copyleft. Conceptually, React is an owned work that invites free labor; you can use their stuff, just so long as you don’t ever conflict with Facebook:

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. Notwithstanding the foregoing, 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.

If that’s a deal-breaker for you (I can think of myriad reasons why it should be) then consider truly open-source alternatives.

Answer to question 2

The verbiage of each individual license has to be treated separately from another. Contact a lawyer for legal advice. If you are unsure of your legal basis, a good place to start might be content that uses tried and tested content licenses.

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