Sanity : Sanity is a headless, real-time CMS where the front end is an open source React-based construction kit and the back end is a graph-oriented cloud data...
TYPO3 : TYPO3 is an enterprise-class, Open Source CMS (Content Management System), used internationally to build and manage websites of all types, from small ...
Metalsmith : An extremely simple, pluggable static site generator.
Plone : Plone is a free and open source content management system built on top of the Zope application server.
Grav : Grav is a modern open source flat-file CMS written in PHP
CMSimple is a content management system (CMS), which requires no database. All data are stored in 2 files, content.htm (content) and pagedata.php (page-related data).