Automad is a open source flat file CMS.
Baun is a modern, lightweight, extensible CMS for PHP.
Fast, Simple, Extensible and Flat-file CMS.
DodgerCMS is a static markdown CMS built on top of Amazon S3.
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
Jekyll is a simple, blog-aware, static site generator.
Kirby is a file‑based CMS Easy to setup. Easy to use. Flexible as hell.
Nesta is a Ruby CMS for developers and designers.
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.
PieCrust is a static website generator and flat-file CMS.
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.
Sphido is a rocket fast, lightweight, flat file CMS for PHP
Stacey is a lightweight content management system.
Statamic is Comercial FFCMS.
Wintersmith is a flexible, minimalistic, multi-platform static site generator built on top of node.js.