The culmination of such an approach is realized in the Beaker Notebook (<a href="http://www.beakernotebook.com" rel="nofollow">http://www.beakernotebook.com</a>). You can not only switch between languages, but the environment allows you to share datasets between Groovy, Python, JS, Julia, Ruby etc ..<p>It's a work in progress, but something to watch out for, imho