Tendenci is an open source CMS system built specifically for Associations and Nonprofit Organizations.
Tendenci contains the online features most requested by NPOs - donor management, email communications, event hosting, photos/videos, memberships and job boards - in an open source format. These modules are available in the fully functional free version of the software so that the average NPO can launch and maintain a website, including the required functionality, without having to locate, install and integrate multiple plug-ins. A clean user interface allows for easy data management and reporting. The open source aspect allows NPOs to further extend the software, modifying the code to meet their specific needs.
Originally built in 2001 as a proprietary product in ASP, Tendenci was rewritten in 2009 for the open source market. The technology behind the new version of Tendenci is Django/Python/Postgres deployed on Ubuntu. The hosted version runs on top of Heroku in the Amazon cloud. For self-hosting, Tendenci runs on any platform that supports the Django/Python/Postgres/Ubuntu stack. As of November 2011, Tendenci is on version 5.1, licensed GPL and available for download on github.
The business model is similar to that of Wordpress, Drupal or SugarCRM. A hosted solution. Advanced professional services. But also a fully functional and extensible open source version available for download. The free version provides resources for NPOs in developing countries that have limited funds and are frequently running on older donated hardware.