Software
WonderCMS
WonderCMS is the smallest flat file content management system. The CMS is built with PHP and has been developed since 2008. No initial configuration required to setup the WonderCMS, the installation is straight forward and simply requires you to unzip and upload 5 files.All data within WonderCMS is structured as JSON format and the flat file nature of the content management system also allow you to migrate hosts easily by transfering files across, no database migration required.
Bludit
Bludit is a content management system that allow you to build your own website or blog in seconds, it's completely free and open source. Markdown support. The flat file architecture of Bludit makes your websites extremely fast, while still allow you and your team to manage content the way you would in other popular content management systems like WordPress, Joomla and Drupal. Without relying on databases like MySQL or complicated DevOps workflows.
Quanta CMS
Quanta is a free, open source Content Management Framework thought for programmers and used for the creation of new-generation websites and applications.
ButterCMS
ButterCMS is a commercial headless content management system and content API. With ButterCMS you can quickly setup your very own headless CMS that supports In-browser editing. Where you can quickly find and filter your images and files, update and schedule content and serve you assets over a content delivery network.
Django CMS
Django CMS is a free and open-source content management system build on the Python web framework Django. With Django CMS, you can create your own website or blog in a matter of minutes which is easy to maintain far into the future. If you are a developer utilizing the Django framework you can integrate Django CMS into an exiting Django application and take advantage of it's publishing and editing features.
OpenCMS
OpenCMS is based on Java and XML technology that allows you to build highly customizable and interactive websites and portals. The open-source content management system includes a WYSIWYG editor and fully-featured Template Engine which is fully compliant with W3C standards.
Strapi
Strapi is a free and open source headless CMS developed with JavaScript for Node.js. The software makes it really simple to generate REST and GraphQL APIs. Simply create your database schema and relationships in the Strapi admin panel UI, and Strapi will auto-generate API endpoints to represent the data structures provided. Strapi comes packed with features you come to expect from normal CMS's such as authentication, authorization, content management and a media library. The software can be used for free and can be self-hosted on any server and platform. Extra enterpise functionallity is currently being developed, and will be sold at cost.
ShoutCMS
ShoutCMS was created for entrepreneurs who are frustrated with business software by combining the most important aspects into one tightly connected platform.
Textpattern
Textpattern is an elegant content management system that is free, open source software. Textpattern is designed to be flexible with powerful tag-based templates that allow you to structure data and manipulate content. The content management system itself can also be extended with the use of plugins, that allow anyone to improve core functionality or add new features. Textpattern already have hundreds of available community built plugins that can be used to improve your website today.
Cockpit
Cockpit is a self-hosted headless and api-driven CMS. With Cockpit you can manage any structured content for your website, web app or mobile application. Cockpit's intuitive dashboard allow anyone to manage content without technical skills and is a perfect match for developers and teams looking to improve they content management situation. Cockpit allow you and your team to setup a content management system for static sites and JavaScript-based front-ends in no-time.