2
Actually it's really a challenge to make modules and themes work between XOOPS 2.0, 2.2, or 2.0.15. So, Drupal or Joomla... Hummm !?...
You should look for
XOOPS Cube which already manage old XOOPS 2.x code through a Legacy module and it plans to offer such solution. Behind XC, there's a programmer in charge of the task, while coders helping fix the thing...
I like people more than machines or money. But that's me!
Lets do something good and great: Lets do open source!