Try_jade_and_stylus is a project mainly written in JavaScript, it's free.
Simple Node.js app to experiment with Jade and Stylus in the spirit of http://haml-lang.com/try.html and http://sass-lang.com/try.html
You can try this online at http://try-jade-and-stylus.herokuapp.com/
It's probably horribly insecure, please don't break it :-)