Concrete 5 CMS

Concrete CMS is a self‑hostable, open‑source content management system released under the MIT license. It provides a web‑based interface where content creators, designers, and developers can build, author, and publish sites using a WYSIWYG editor that works directly on the page. The platform includes built‑in features for editing, version control, and role‑based permissions, allowing teams to collaborate on content without needing additional extensions.

The system emphasizes security and compliance, offering out‑of‑the‑box support for standards such as ISO 27001, SOC 2, and HIPAA, and it can be deployed on hosting configurations that meet specific organizational requirements. Its architecture is designed for easy installation via Composer, and the repository contains the current 9.x codebase with legacy branches for earlier releases.

Concrete CMS targets teams that need a free, stable CMS with robust collaboration tools and strong security guarantees, while remaining accessible for editors to learn quickly and for developers to extend as needed.