We created three sites, Jabalpur.net.in (WordPress) Amritsar.net.in (Drupal) and Vadodara.net.in (Joomla). Each website was created with a similar amount of content, similar Overture results and a similar domain name.
Within two weeks the WordPress site was so far ahead that it looked as if they competition was over. Slowly however, Drupal and Joomla have recovered until they now lead the pack. The Joomla site is now #1 for 6 of its 9 keywords in Yahoo India and the Drupal site has two top-10 rankings in every search engine we measure except for Yahoo.
All of this makes me wonder – can and do search engines distinguish between different forms of software? Does Google penalize a blog (WordPress) site if it is not updated in two months, whereas it doesn’t expect such frequent updates from a CMS (Drupal and Joomla)?