[smarx]

I think this is what you're asking for:

    <div id="root"></div>
    <script src="https://unpkg.com/react@16/umd/react.development.js"></script>
    <script src="https://unpkg.com/react-dom@16/umd/react-dom.development.js"></script>
    <script src="https://unpkg.com/babel-standalone@6.15.0/babel.min.js"></script>
    <script type="text/babel">
      ReactDOM.render(
        <h1>Hello, world!</h1>,
        document.getElementById('root')
      );
    </script>

[ch4s3]

This is essentially what I meant. I think it's a great way to approach hacking on and learning React, Vue, or similar.