javascript compare graphically two JSON/XML objects

I am trying to build a web application that a JavaScript graphical comparison/representation of two XML/JSON data obje开发者_如何学Pythoncts, so the user would be able to merge between them. Does anybody know about any available code that does something like this?

I'll take a stab, but the question isn't too clear... Compare the two XML strings with this: http://snowtide.com/jsdifflib