CiviCRM

CiviCRM is a constituent relationship management system for nonprofits, NGOs, and advocacy organizations. It keeps constituent records, contributions, memberships, events, and outreach together in one place, with fundraising and supporter tracking as the central use case.

It runs as a standalone PHP web application or as an integrated module inside Backdrop, Drupal, Joomla, or WordPress, so groups can use it on its own or alongside an existing content management system.

CiviCRM is self-hosted on your own server and coordinated by CiviCRM LLC. It is released under the GNU AGPL 3 license, with downloads and installation guides on the project site.