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.
Metalsmith - An extremely simple, pluggable static site generator.
Grav - The modern open source flat-file CMS
Nikola - Nikola is s static site generator tool written in Python.
Bludit - Bludit is a web application to build your own website or blog in seconds, it's completely free and open source. Markdown support.
GatsbyJS - Blazing-fast static site generator for React