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.
CiviCRM is an open source and freely downloadable constituent relationship management solution. CiviCRM is web-based, open source, internationalized, and designed specifically to meet the needs of advocacy, non-profit and non-governmental groups.
Advokit is a free web-based voter contact management system created by and for the grassroots. Using Advokit, you can combine the power of voter files and social networking to build your grassroots into an organization, to identify and obilize supporters.