[numair]

Haven't we learned by now, my fellow HN readers? All of Facebook's open source "gifts" are patent Trojan horses. Go take a look at their PATENTS file before going anywhere near this stuff.

The fact that Facebook, at such a level of wealth and success, gets away with this stuff is despicable. It's also an insult to the great legacy of companies like Sun, which gave freely without strangling its beneficiaries. It says a lot about the culture and leadership at the company, but that's been well-documented...

If you're a passionate engineer at Facebook working on an open source project, please go work on it somewhere else!

[superuser2]

False. They fixed it about a month ago.

>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.

Source: https://github.com/facebook/PathPicker/blob/master/PATENTS

See also the announcement of the change: https://news.ycombinator.com/item?id=9356508

[lstyls]

Even if this was the case (this was poor wording in the original PATENTS which has since been fixed) you are only subject to these constraints in any code you provide that includes the source code. Since this is a shell tool, that is largely irrelevant. For the same reason, you can compile and release binaries from closed source binaries using gcc even though it is licensed under GPL.

[Eduard]

What is a patent Trojan horse? I just read the PATENTS file, but cannot think of a scenario that could affect me negatively. Can you give one?

[mcintyre1994]

(IANAL, I did complain here about the old patents file)

An older version of their patents file used language that suggested to some that the license would be void if you attempted to defend against a patent suit from Facebook and it could therefore be dangerous to use.

They recently updated the file to clarify some terms, particularly the one the parent is complaining about, and I haven't heard anybody complaining about the new language.

[xxbondsxx]

Yep, we had a bit of a brouhaha over the original update to our patents file and clarified the language afterwards, I think it's a bit more straightforward now!