React Babel
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8" />
<script src="https://unpkg.com/react@17/umd/react.development.js"></script>
<script src="https://unpkg.com/react-dom@17/umd/react-dom.development.js"></script>
<script src="https://unpkg.com/babel-standalone@6/babel.min.js"></script>
<title>React </title>
</head>
<body>
<div id="root"></div>
<script type="text/babel">
ReactDOM.render(
<ul>
<li>HTML</li>
<li>CSS</li>
<li>Vanilla JS</li>
</ul>,
document.getElementById("root")
);
</script>
</body>
</html>
see Babel compiler
Compiler