Argo CD is a CNCF-graduated Kubernetes-native GitOps continuous delivery tool that uses Git repositories as the single source of truth for declarative application deployment, auto-sync, multi-cluster management, and security compliance.
Spinnaker is Netflix's open-source multi-cloud continuous delivery platform supporting advanced deployment strategies and automated release management across AWS, GCP, Azure, and more.
Screwdriver CD is Yahoo's (now Verizon Media) open-source continuous delivery platform with container-native builds and declarative pipeline configuration.
GoCD is ThoughtWorks' open source continuous delivery server known for visual pipelines, value stream mapping, and complex deployment strategy support.
CloudBees is the enterprise Jenkins automation platform provider, offering a security-hardened Jenkins distribution and CloudBees CI/CD managed services for enterprise DevOps.