It would be great to see a timeline, where each method invocation leaves a colored point behind it. So there would be colored trails as time progresses. Then it would be useful to spot methods that are called too often. Or to quickly see the call stack. ESP if you could zoom in and examine the recorded history. That would be so much better than stepping through a debugger.

Also if it was injectable via a bookmarklet into a running backbone application. That would make it a great debugging tool.

Bonus points : click on a method to see the source code

Hey there, I'm the developer of a browser based IDE called pixelJET. I was researching visual JavaScript debugging concepts to integrate into pixelJET when your post came up on HN.

It's not really a real world applicatoin yet, but if it helps, your post inspired me gave me some ideas for integration into the product. If I publish anything I'll be sure to give you a shout out :)

A couple of thoughts for the demo, it would be cool to see the actual JavaScript source code too, so you could get a feel for what the visualisation is showing you. Also, noting which functions were event handlers would be useful, although a bit tricky.