Sitecake - Drag and drop CMS for HTML websites. It's flat file CMS so it's pretty fast.
inRiver - inRiver offers product information management solutions helping B2C and B2B multi-channel commerce tell perfect stories across channels.
ClassicPress - The WordPress fork. No Gutenberg. Great future!
Pimcore - Pimcore is an award-winning data management and customer experience management software.
TYPO3 - TYPO3.com - Infos, SLAs, Extended Support Versions and more
Webcollage - Webcollage is a SaaS solution enabling brands to manage rich product information and publish it in real time to retailer websites.