Edit in JSFiddle

var Hello = React.createClass({
  render: function() {
    var name = "Tercel";
    return <div>Hello {name}.</div>;
  }
});

ReactDOM.render(
  <Hello />,
  document.getElementById('hello')
);

<script src="https://facebook.github.io/react/js/jsfiddle-integration-babel.js"></script>

<div id="hello">
</div>