Yes ,Drupals is one software that uses for organize large community type website. Drupal is a free software package that allows an individual or a community of users to easily publish, manage and organize a wide variety of content on a website. Tens of thousands of people and organizations are using Drupal to power scores of different web sites, including * Community web portals * Discussion sites * Corporate web sites * Intranet applications * Personal web sites or blogs * Aficionado sites * E-commerce applications * Resource directories * Social Networking sites Get latest veriosn of this software here http://drupal.org/project Good Luck