This document provides an overview of popular contributed and core modules for the content management system Drupal. It is organized into sections on administration, content management, performance, navigation, publishing, user management, SEO/analytics, events/calendars, authentication, and library-specific modules. Key modules highlighted include Views, CCK, Context, Panels, Webform, Taxonomy Menu, Pathauto, Organic Groups, Google Analytics, Date, Calendar, LDAP, and library-focused modules like LT4L, Question/Answer for email reference, and Fedora REST API. Resources for learning more about Drupal like books, online tutorials, communities and publications are also listed.