Even in the Ubuntu Server 9.04 there is a nice LAMP option with Apache, PHP and MySQL, some more steps are necessary to turn Ubuntu Server 9.04 into a real Drupal development environment. After these steps, you will have a development server, where all Drupal versions, unlimited number of domains and development projects can be set up. Use this tutorial to get a more sophisticated Drupal development environment. And don't forget, there is a simple way in Ubuntu 9.04 for Drupal 6: sudo apt-get install drupal6