I think the spirit is that patents are not legitimate. Suing for patent infringement is not considered exercising a legal right, it's considered being a dick and vandalizing someones property. So this is not to be read like a contract between to businesses, but like a truce.

It might as well say "we agree to not destroy your business using dirty tricks if you don't attempt the same".

Of course, opinions on that are divided...

That's how Apache 2.0 and GPLv3 treat patents. The language in the React license is not symmetric like the above licenses and thus doesn't feel like it's a "screw you" to patents. Not to mention that Facebook is very patent-heavy and it doesn't feel like they're anti-patent in any meaningful way.

I'd be more sympathetic to Facebook if they declared they would never use patents to sue someone and they'd only use their patents "defensively". Of course, they'd never do such a thing even though such a statement has zero weight.

> Suing for patent infringement is not considered exercising a legal right, it's considered being a dick and vandalizing someones property. So this is not to be read like a contract between to businesses, but like a truce.

This is an oversimplification. There are plenty of mum and dad inventors who would get destroyed by large companies but for relying on patent protection for their life's work.

Of course. I'm not claiming it is so. I'm just saying, if you think so, then you are likely to come up with such a license.

> Why is it sane to lose the patent grant if you are a aggressor in a patent lawsuit against Facebook (for any patent, even ones unrelated to React)?

Why should Facebook support companies that are suing them?

Counterpoint - why would I want to build my business on software that, if the parent company screws me in some unrelated way, I have no recourse but to rebuild my entire software portfolio, or just accept that I've been screwed?

If they were offering something unique or especially distinctive, then maybe it would be worth risking, but as there are half a dozen or so alternatives, why bother putting myself into that particular pickle?

> Counterpoint - why would I want to build my business on software that, if the parent company screws me in some unrelated way, I have no recourse but to rebuild my entire software portfolio, or just accept that I've been screwed?

This doesn't prevent you from suing. It just prevents you from suing over patents.

Because they already allowed other people to use it, and it doesn't required extra effort on Facebook's part to allow another company to use it.

I can understand why Facebook would want to have a clause like this (to discourage lawsuits against them), but I would consider it against the spirit of open source to do so (ie. Facebook should be able to continue to do this, but I wouldn't consider React to be open source software in that case).

I wonder, does the definition of "open source" or "free software" require any patent grant at all?

I guess the GPLv3 has provisions for patents, but older licenses didn't. I remember some controversy around open source video codecs that you were not able to use safely because they were infringing patents.

Patents can be used to restrict all four of your freedoms under the FSF definition of "free software". They have written about this problem for quite a long time[1,2]. The problem with patents for things like formats or protocols is that they make free software implementations potentially dangerous to use (users can be sued for violating a patent). That's why h264[3], MPEG-whatever, FLV, etc are all considered to be bad even though they have free software implementations. MP3 recently shedded its patent licenses[4], and the response was that every distribution finally packaged mp3-lame in their main repos.

GPLv2 didn't have a patent grant because it wasn't a very well-known issue in 1991. Apache 2.0 was the first free software license to have a patent grant (which unfortunately made it GPLv2 incompatible) but GPLv3 included a similar (though stronger) patent grant because of Apache 2.0.

While these may sound like theoretical problems, people have been sued over using GIF, MP3, etc before. Every time you install Firefox, it will download a free software binary from a Cisco server that does h264 decoding[5]. However, they cannot legally recompile the binaries themselves as it means that the patent grant no longer applies and Mozilla (or your distribution) could be sued -- even though the binary's source is BSD-licensed.

[1]: https://www.gnu.org/philosophy/fighting-software-patents.htm... [2]: https://www.gnu.org/philosophy/danger-of-software-patents.ht... [3]: https://www.fsf.org/licensing/h264-patent-license [4]: https://www.iis.fraunhofer.de/en/ff/amm/prod/audiocodec/audi... [5]: http://www.openh264.org/index.html