I wrote Pdf2Jpg.net, an online PDF to JPG converter, almost two years ago.
I primarily used PHP alone: plain old PHP files, direct access to MySQL... The web site works pretty well, converting PDF to JPG all day long.
Yet I wanted to make the site architecture more scalable, and also to take advantage of existing components. So I've undertaken to rewrite Pdf2Jpg.net on top of Drupal.
I completely new to Drupal so I'm still coding at the moment, in a trial and error fashion. I hope the new version will be online soon! You can have a look to the existing version for now, just to compare it to the new version when it's done. Stay tuned!