Concrete CMS

Concrete CMS — formerly known as concrete5 — is a self-hosted, MIT-licensed content management system written in PHP. It is built around in-context editing: instead of working in a separate admin panel, editors browse the live site, click into the page and change text, images and blocks in place, with drafts and page version history behind every change.

Sites are assembled from blocks dropped into areas and layout grids, with page types, page templates, reusable stacks and global areas providing structure, and themes supplying the design. Permissions are configured per page, area and block rather than only per role, so a client can be allowed to edit one campaign page without touching the rest of the site. The core also ships form building, a file manager with basic image editing, conversations, notifications, full-page caching, multisite, multilingual content and a built-in REST API with OAuth2 authentication and scoped access.

Extending the platform happens through the Concrete Marketplace, which serves themes and add-ons and needs Concrete 9.3 or later for marketplace integration, or through custom packages, blocks and console commands for teams that prefer to build their own. Installation is a zip download or a git clone followed by composer install, against MySQL or MariaDB, and official hosting is available from PortlandLabs if you would rather not run the server yourself.

Compared with Squarespace, Wix or Webflow, Concrete CMS gives you the code and the database: no per-site subscription, no platform lock-in, and full control over templates and server configuration, in exchange for handling hosting, updates and backups. Compared with WordPress it ships its block editing, page types and granular permissions in core rather than relying on a stack of plugins.