Earlier quoted context omitted.
Alternatively there's this: https://github.com/developit/preact Preact is a fast 3kB alternative to React, with the same ES2015 API as that of React. Preact is MIT licensed and does not have any additional conditions beyond that.
It's debatable how far that provides indemnity from Facebook. It's explicitly derived from their API, so whereas you can conceivably write a project to make use of React and then seamlessly switch to Preact if Facebook become threatening, surely Preact itself is liable — and your software by extension — for using the API?
https://www.techdirt.com/articles/20160511/17515734410/stake...