[barneycarroll]

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?

[confounded]

It does appear that in the US, APIs are considered subject to copyright, thanks to Oracle:

https://www.techdirt.com/articles/20160511/17515734410/stake...