Sitecake - Drag and drop CMS for HTML websites. It's flat file CMS so it's pretty fast.
Readymag - Readymag is a design toolkit that helps create immersive digital experiences without developers in days, not weeks.
ClassicPress - The WordPress fork. No Gutenberg. Great future!
FlippingBook - FlippingBook changes the way you present your documents
TYPO3 - TYPO3.com - Infos, SLAs, Extended Support Versions and more
Publitas.com - Publitas helps you to drive more visitors to your online store by publishing catalogs online.