There are scenarios where refreshing page to see results of your updated code is just too painful. This could be coding a mobile HTML5 app, or inside of facebook canvas.
Here is the github repo.
This is how you can used it: after setting up your node.js server, put this code on the page you would like to remotely control:
<div id="content"></div> <script src="http://localhost:8083/js/init.js"></script>
And then through the code.html page "inject" HTML/CSS/JS into the remote page.