WordPress - WordPress is web software you can use to create a beautiful website or blog. We like to say that WordPress is both free and priceless at the same time.
Cloud Cannon - Cloud Cannon turns Dropbox/Git-project into a CMS you can setup in seconds
Grav - The modern open source flat-file CMS
Netlify CMS - An open-source CMS for your Git workflow
Bludit - Bludit is a web application to build your own website or blog in seconds, it's completely free and open source. Markdown support.
Strapi - Strapi is the most advanced Node.