Free and Open Source Software
Fork CMS
Fork CMS is a free and open-source, easy to use content management system built with PHP and Symfony Components. The content management system features an intuitive administration panel that makes it easy to create and manage content for the web. Fork CMS also comes packed with apps that can be installed to extend the feature set of the content management system.
Joomla
Joomla is a free and open-source content management system written in PHP. The CMS is built entirely by volunteers from all over the world and has a strong community that provide educational resources, and extensions.
Ponzu CMS
Ponzu is a powerful, free and open-source HTTP server framework and CMS. It provides automatic, free, and secure HTTP/2 over TLS with Let's Encrypt, a useful CMS and scaffolding to generate content editors, and a fast HTTP API on which to build modern applications.
TinaCMS
Tina is an open-source site editing toolkit and headless CMS for React-based sites like Gatsby & Next.js
Storyblok
A headless & API-based CMS with an opt-in head and a visual editor. With Storyblok you can manage your content through an intuitive dashboard and access that data though the content delivery API, as nested JSON. Storyblok is an open-source software and can be used as such, but is also provided as a commercially hosted, cloud rendering service. As a front-end developer you can choose to work with any template engine, framework or system of your choice.
FeinCMS
FeinCMS is a bare bones content management system written in Python on-top of the web framework Django. The CMS is built to know nothing about your content, and includes an admin interfaces that can handle content types. It lets you reorder page content blocks using a drag-drop interface, and you can add as many content blocks to a region (sidebar, header, etc) as you want. FeinCMS was built this way to allow for maximum flexibility, where developers, designers and content managers can create a unique site, tailored for their type of content and future patterns.
FrontAid CMS
FrontAid CMS is a decoupled and Git-based content management system. Content is stored in your own Git repository in the JSON text format. It works with all your current tools and you always own your data.
CushyCMS
CushyCMS is a FREE hosted content management system that's actually easy to use, fast to setup and doesn't require programming skills.
October CMS
October is a free, open-source and self-hosted content management system written in PHP on top of the framework Laravel. The CMS features a universal extendable dashboard, inspector, reusable CMS components and a plugin system that can be used to extend functinality of your website. The plugin store contains thousands of community-made plugins that can either be purchased or installed for free. As a data store, October CMS supports MySQL, PostgreSQL and SQLite.
Revize CMS
Revize is a web-based content management software designed for municipalities.