The paradigm is everywhere, so just use another library that uses that paradigm, like Inferno or Preact, or even something slightly different like Vue if you want.
The point is those other libraries could be in violation of any patents that Facebook may or may not have with regards to React. Perhaps they have a patent on virtual DOM? That would mean your usage of Inferno, Preact, Vue, or Angular 2+ would violate the patent.
That would frankly be impossible. All JSX boils down to is h(name, properties, children) and that is literally it. Each reconciler is different, uses another v-dom, etc. If you wanted to patent react, you patent the mere use of functions. And not just that there are about 20 years of fair use of similar principles, even for jsx in particular which evolved from mozillas e4x and otherwise keeps to basic xml markup and mustaches.
Also impossible because JSX is independent of React. The specification is only subject to a standard Copyright and is released under the Creative Commons Attribution 4.0 International license.
