Khan Academy has a pretty amazing live environment inside the browser: http://khanacademy.org/cs http://khanacademy.org/cs It's been tested to work pretty well

Khan Academy has a pretty amazing live environment inside the browser: http://khanacademy.org/cs http://khanacademy.org/cs It's been tested to work pretty well with middle school children, so it seems right up your alley. John Resig (creator of jQuery) made it happen, his blog post on it: http://ejohn.org/blog/introducing-khan-cs/ http://ejohn.org/blog/introducing-khan-cs/