Automad is a open source flat file CMS.
Baun is a modern, lightweight, extensible CMS for PHP.
Fast, Simple, Extensible and Flat-file CMS.
A blogging engine that saves your posts as simple text files.
The Simplest Content Management System. Ever.
A Powerful, Lightweight, Flat-File CMS with True-WYSIWYG.
Grav is a modern open source flat-file CMS
HTMLy is an open source databaseless blogging platform. The Flat-File Blog and Flat-File CMS written in PHP.
Hugo is a Fast and Flexible Static Site Generator
Kirby is a file‑based CMS Easy to setup. Easy to use. Flexible as hell.
la.plume is a small, open source flat file system to build fast, simple websites
Mecha is a file-based CMS.
Monstra is a modern and lightweight Content Management System. It is Easy to install, upgrade and use.
Nesta is a Ruby CMS for developers and designers.
Nibbleblog is a powerful engine for creating blogs, all you need is PHP to work.
With Parvula you can create a quick website from markdown files.
PhileCMS is a file-driven CMS. Powered By Markdown And Twig. But You Can Change That.
Pico is a stupidly simple & blazing fast, flat file CMS.
Pluck is your small and simple content management system, written in php.
Pulse CMS is the easiest way to build and deploy a responsive, content managed website.
Sculpin is a static site generator written in PHP.
Singularity is a simple (single PHP file), flat file CMS which marks up HTML using Markdown.
Stacey is a lightweight content management system.
Statamic is Comercial FFCMS.
WonderCMS is the smallest CMS in the world