Jekyll is a simple, blog aware, static site generator. It takes a template directory (representing the raw form of a website), runs it through and Liquid converters, and spits out a complete, static website suitable for serving with Apache or your favorite web server.
Grav is an easy to use, yet powerful, opensource CMS that requires no database. In a nutshell, installing Grav is a matter of unzipping the file. It is fast, has sophisticated caching, and a light footprint for optimal performance.
Gatsby provides development teams an open source frontend framework for creating dynamic, optimized websites and a cloud platform for delivering them on a blazing fast edge network.
Vapid is an intentionally simple content management system built on the idea that you can create a custom dashboard without ever leaving the HTML.Discontinued
Last update 2015, according to the homepage.
Backdrop CMS is a simple, lightweight, and easy to use Content Management System used to build attractive, professional websites. Use it for everything from a single-administrator's personal blog site, to a complex, multi-role, business e-commerce platform.