Edit in JSFiddle

HTML
Result
  <body>
    <div id="content">

    </div>
    <script type="text/babel">
      // tutorial1.js
var CommentBox = React.createClass({
  render: function() {
    return (
      <div className="commentBox">
        Hello, world! I am a CommentBox.
							<h1>Comments</h1>
        <CommentList />
        <CommentForm />
      </div>
    );
  }
});

var CommentList = React.createClass({
  render: function() {
    return (
      <div className="commentList">
        Hello, world! I am a CommentList.
      </div>
    );
  }
});

var CommentForm = React.createClass({
  render: function() {
    return (
      <div className="commentForm">
        Hello, world! I am a CommentForm.
      </div>
    );
  }
});

ReactDOM.render(
  <CommentBox />,
  document.getElementById('content')
);
    </script>
  </body>