Sitecake - Drag and drop CMS for HTML websites. It's flat file CMS so it's pretty fast.
Elementor - Elementor is a front-end drag & drop page builder for WordPress.
Textpattern - Textpattern is an elegant content management system that is free, open source software.
Divi Theme - A flexible WordPress theme with the power of Divi Builder built in.
TYPO3 - TYPO3.com - Infos, SLAs, Extended Support Versions and more
Brizy - The effortless way to build WordPress websites visually