But will not go into the question of "what's the best Drupal or Joomla"
Brian Teeman is one of the founders of Joomla and is invited to speak at major Drupal conference in Munich. The name of the lecture is "Joomla! - Hippies, Pirates, Revolutionaries or a Distributed Community" where Brian Teeman will share their personal experiences of Joomlaprojektet.
Furthermore writes Teeman on his blog he does not see himself as a missonär to lead the lost into the right path. Instead he presented the similarities between Drupal and Joomla CMS, both of which are based on open source and whose goal is to make the Web more accessible to everyone.