ClassicPress - The WordPress fork. No Gutenberg. Great future!
logit.io - Logit.io provides complete observability of logs, metrics and traces. The platform also offers alerting & monitoring, as well as Prometheus, OpenSearch & Grafana. Ingest any type of data to see real-time insights about your applications and services
Sitecake - Drag and drop CMS for HTML websites. It's flat file CMS so it's pretty fast.
CXGuardian - CXGuardian is a platform powered by QualityKiosk Technologies and allows users to monitor their mobile and web-based applications’ performance.
TYPO3 - TYPO3.com - Infos, SLAs, Extended Support Versions and more
AppOptics - Application performance management and infrastructure monitoring.