Open Source Software for PHP
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.
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.
PhpSQLiteCMS
phpSQLiteCMS - a simple & lightweight CMS
Bear CMS
Bear CMS is a self-hosted content management system that seamlessly integrates with your website. With Bear CMS you own your data and content, which is store on your own server. Your websites and Bear CMS's management tools integrate seamlessly and creates an experience that content managers and editors will enjoy.
MODX
MODX is a free, open source content management system and digital experience platform. The CMS gives you full control over your creative, editorial vision and the experience you deliver. MODX is written in the programming language PHP and supports both MySQL and Microsoft SQL Server databases. The CMS is openly developed and released under the GPL license, and allows contribution.
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.
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.