James! This is great work! I would love to see where this goes! Please consider adding support for terminal emulators!! It would make a killing and potentially give Codecademy a run for its money!
Thanks! I'm adding a "custom iframe" feature over the next week or so. This lets anyone build any kind of interactive block, such as terminal emulators, code editors/runners, etc. Stay tuned; email me if you want me to let you know when it's out! - Jim