Backdrop CMS

Backdrop CMS is a PHP‑based content management system that enables non‑technical users to create and maintain a variety of websites, from blogs and image galleries to intranets and social networks. It runs on PHP 7.1+ with MySQL 5.5+ (PDO) and works with Apache or Nginx, requiring as little as 15 MB of disk space. The platform provides an out‑of‑the‑box installation experience, a codebase that can be learned quickly, and extensible APIs for adding functionality.

The system targets small to medium‑sized businesses, non‑profits, schools, museums, and similar organizations that need a flexible, self‑hosted solution without subscription fees. It offers a large ecosystem of modules—over 1,300 add‑ons—maintained by an active community, and includes a built‑in upgrade path from Drupal 7 for sites migrating from that platform.

Backdrop is released under the GPL‑2.0 license, is free to host, and emphasizes performance on shared hosting, ease of content management, and community‑driven development. Documentation, forums, and regular virtual office hours support users and contributors alike.