Concrete 5 CMS

Concrete CMS (formerly Concrete5) is a free and open source content management system designed for teams that want to give non-technical editors real control over their websites. It ships with an in-browser editor that lets users edit text and images directly on the page, plus a drag-and-drop block system for adding things like galleries, forms, and navigation. The CMS handles everything from simple brochure sites to large corporate portals.

Concrete CMS runs on PHP and MySQL or MariaDB, and it works on Linux or Windows servers. It supports multisite setups, granular user permissions with workflow approvals, and a block-based layout system that doesn't require templates or code changes. The platform includes built-in SEO tools, caching, and a marketplace for themes and add-ons. The project is maintained by Portland Labs, the company behind the software.

This CMS is a strong fit for agencies and organizations that need to hand off site management to content editors without developer support. The core software is free under the MIT license, with paid add-ons and cloud hosting available from the developer. It powers over 100,000 active websites and has an active community contributing to its GitHub repository.