Grav - The modern open source flat-file CMS
Strapi - Strapi is the most advanced Node.
Bludit - Bludit is a web application to build your own website or blog in seconds, it's completely free and open source. Markdown support.
Contentful - You don't need another CMS. You need a better way to manage content — unified, structured, and ready to deploy to any digital channel.
HTMLy - HTMLy is an open source databaseless blogging platform. A Flat-File Blog and Flat-File CMS written in PHP prioritizes simplicity and speed.
DatoCMS - Connect DatoCMS to your favorite site generator, build the perfect backend and deploy anywhere you like.