Grav (License: Free)
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. Content is just simple markdown files in folders, with no complicated databases to deal with. A powerful API and extensive hooks allow for plugins to extend Grav and a comprehensive package manager provides easy installation and updating of extensions. Flexible Twig templating allows easy realization of your designs.