React is under BSD, but includes additional terms in a PATENTS file. Very generous terms. And yet ...
I'm not a lawyer, I couldn't even play one on TV. But it is profoundly bloody annoying that they didn't pick a well-understood, well-known license instead of baking up their own Frankenlicense.
I'm sure their lawyers have a reason for not just using the Apache 2 license. I'd love to know what it is.
In the meantime, every single company with fastidious lawyers is going to be dealing with Legal yanking the emergency brake when they see React, because it does not neatly fit into a known license.