Ecosystem health of Drupal

Hi all,

I'm a student and I have to establish a comparison of the software ecosystem health of Drupal and compare it to Joomla's.
Most of you probably don't know what a software ecosystem is. You can find a definition here : http://en.wikipedia.org/wiki/Software_ecosystem

For that purpose, I will use different metrics based on the result of data mining.

I'm posting here because I'd like to know if any of you could advise me an approach to retrieve data over Drupal (users, modules, etc) ?
I can use any language to build my own tools for that purpose.

Thank you for reading