My website is database driven and coded in PHP/MySQL. If i wanted to start coding in Ruby on Rails or Python will i be able to change my site’s source code in to RoR or Python. My site is large and has video uploading system and social network features, including forums.
1. Is it possible?
2. How long would it take?
3. Is it Expensive?
4. Can it be done easily?
Thank you.

Whenever I search for PHP source level debugging, it seems to point me to either Xdebug or Zend. But I can never seem to find a current, valid set of instructions on setting it up.
I want to do source level debugging of my PHP code, on my Mac OS X 10.5.6, MacBook Pro. Has anyone actually succeeded at this themselves?