I have an idea for a project that has to do with helping people learn to program. One of the things I think would be cool would be to have a place on the site where you can edit JavaScript code in real time in your browser.
I know there are a number of web-based JavaScript editors, but I haven't been able to find out if there are any tools that let you debug JavaScript from your browser. I think being able to step through your code is a valuable learning experience for people who are new to programming. It seems like something along those lines should be possible, though.
I originally thought you could use something like Firebug Lite: http://getfirebug.com/firebuglite, but they don't support debugging. Is this just too hard of a problem to solve in JavaScript?
I suggest you try Cloud9. It is a full-featured web based IDE for Javascript, which includes a great debugger. It is free for open source projects, which I imagine would include most learning purposes.