diff and syncing between 2 CQ instances?

Hi everybody,

I have two different CQ installations (one is production instance, the over is a development instance).  

Given a JCR path, I would like to generate a report that would report the differences between the 2 JCR repositories at the given path.  I would like to use this report to also build a package, or somehow automate a process to copy content from one jcr repository or the other.

I was hoping that somebody may have already written a plugin/program that would do this.

Thanks!