Nesta

A fast static site generator in a single binary with everything built-in. https://www.getzola.org

Modern, Crazy Fast, Ridiculously Easy and Amazingly Powerful Flat-File CMS powered by PHP, Markdown, Twig, and Symfony

TinaCMS is the leading open-source headless CMS that supports Markdown and Visual Editing. Your content is stored in your own GitHub repo

Front Matter is a CMS running straight in Visual Studio Code. Can be used with static site generators like Hugo, Jekyll, Hexo, NextJs, Gatsby, and many more...

Publish markdown (and html) websites, docs, wikis and websites in seconds. Integrates with your AI.

Alchemy is the Open Source Rails CMS framework for the component based web that can be used as classic server side rendered or headless CMS.