Earlier quoted context omitted.
If React really is covered by patents Facebook has then Preact is likely infringing on them since it does the same things in similar ways. And Preact doesn't come with a patent grant from Facebook at all.
We learned from Java and Google that you can't patent and API. It's not forked from React it's an alternative.
did we? I think the jury is still out on this, i.e. we had one verdict for google, one for oracle, one for google again, and now there's another appeal.