Backdrop CMS | Free Open Source CMS built in PHP

Backdrop CMS is a free and Open Source Content Management System that helps you build modern, comprehensive websites on a reasonable budget.
Backdrop CMS is being used across more than 3,600+ sites for both individuals and organization of all kinds.
The Backdrop CMS community wrapped up an exceptional year with three releases in 2026 following our steady four-month release cycle, and marking the project's 11th birthday along the way. This year brought a large set of changes in Backdrop's history, with major features aimed squarely at site builders and content editors.