UPDATE 22 Sep, 2017
"Relicensing React, Jest, Flow, and Immutable.js" (MIT license, PATENT file removed)
https://code.facebook.com/posts/300798627056246/relicensing-react-jest-flow-and-immutable-js/
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
- Your license to use React.js can be revoked if you compete with Facebook
- How do you deal with the React patent / licensing issue?
- Why I'm not a React Native Developer (only the small part of the text under headline "Patently daunting")
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:
- Is my interpretation of how this may apply in my situation seems correct?
- 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?