It's definitely a neat idea, but as a Python and JavaScript coder, I don't know how much I would actually use it.<p>For Python, my code tends to rely heavily on modules that aren't found in the Python standard library, which is limited when you're using a REPL that only has vanilla Python.<p>For JavaScript, code that I show tends to be more oriented to DOM manipulation rather than the console, so maybe that could be something that could be implemented?<p>That said, this is probably best for teaching novice programmers, which seems to be the goal anyway with Codecademy. :)<p>Keep up the great work, I really find what you guys are doing to be a huge contribution to education.