https://reactjs.org/docs/add-react-to-a-website.html
Having said that, React is normally used with JSX syntax, which requires a compile step.
You _can_ use it with "raw" `React.createElement()` calls, but that's generally unwieldy and almost no one does that.
However, there's a very neat library called https://github.com/developit/htm , which is an almost-JSX-compatible syntax that uses JS template literal strings, and requires no compile step.
https://github.com/arijs/vue-next-example
I already integrated vue-router, and am currently on the process of fully integrating Vue server renderer. I already have a basic usage implemented, where the home page is compiled to a html string, but I still need to make it easy to compile all pages and to implement client-side component hydration.
https://shinglyu.com/web/2018/02/08/minimal-react-js-without...
So if you want to use it on one page, it's a hard sell to set up all that infrastructure (and document it for the team)
On some sites I've used Vue.js by simply adding a <script> tag with vue.min.js.
On sites already using Gulp or similar, it's pretty simple to incorporate the Vue bundle and use it on one or a few pages.