The document discusses 5 important tools for Drupal development: 1. Drupal Contrib which allows extensions and customizations through community-created modules. 2. Administration Menu which provides a simplified administrative interface through a CSS-based dropdown menu. 3. Drush which is a command line shell and scripting interface for installing, developing and maintaining Drupal sites. 4. Devel Themer which is a theming tool that provides information about template files and theme hierarchy. 5. Drupal for Firebug which extends the Firefox plugin Firebug for debugging Drupal through the browser console.