Grav - The modern open source flat-file CMS
PHPRunner - PHPRunner builds visually appealing web interface for popular databases.
Bludit - Bludit is a web application to build your own website or blog in seconds, it's completely free and open source. Markdown support.
Scriptcase - Powerful web low-code RAD platform. Unleash the power of web development and boost your productivity time creating delightful projects with magnificent BI solutions.
HTMLy - HTMLy is an open source databaseless blogging platform. A Flat-File Blog and Flat-File CMS written in PHP prioritizes simplicity and speed.
AdminLTE - Web-based admin dashboard & control panel template. Highly customizable and easy to use.