Yes you can! Use a CDN like the example in the docs[1].

I've done this for a static site that has some dom manipulation, and it's quite nice as a jquery replacement in that use case.

[1]https://facebook.github.io/react/docs/installation.html#usin...

Yes! You can directly include the React library via a script tag, or however else you want. However, it's definitely most common to use node to bundle your app with webpack, browserify, rollup, etc.