Tools to diff two Keynote '09 slideshows Is there any tool which I can use to effectively diff two Keynote '09 slideshows?

TL;DR

An Apple Keynote (i.e. a .key) file consists of a directory structure which contains all the resources used in a slideshow (i.e. images, videos) and a .apxl file containing the structure and the text of the slideshow, encoded in a given format. Therefore, it should be possible to diff two versions of the same slideshow comparing the list of resources and the XML file. The comparison should give decent information about what has been changed or added between two versions of the same slideshow.

Is there any tool which is able to do some clever (e.g. strip metadata away from the comparison) diffing between two Keynote slideshows?
I ended up writing my own script who does that. It's available at:

https://github.com/robertoaloi/keynote-to-text

Contributions are welcome.