ACK One vs Cluster API

ACK One has no write-up on Specifiction yet; its figures are above.

Cluster API is an open-source project for managing the lifecycle of multiple Kubernetes clusters through declarative APIs and tooling. Platform operators can use it to create, scale, upgrade, and destroy Kubernetes-conformant clusters across on-premises and cloud environments. Provider implementations are interchangeable; kubeadm is the default bootstrap provider. The ecosystem includes infrastructure, bootstrap, control plane, IPAM, addon, and runtime extensions, with environments such as AWS, Azure, GCP, OpenStack, vSphere, and KubeVirt. A management cluster can use clusterctl or the Cluster API Operator to manage provider components. Clusterctl fetches provider component YAML and installs it, while the Operator uses a declarative approach intended to support GitOps workflows. Getting started requires an existing Kubernetes cluster accessible through kubectl; kind, Docker, and Helm are common prerequisites. Cluster API supports multi-cluster provisioning and upgrades, but does not manage a single cluster spanning multiple infrastructure providers or clusters it did not provision. It is free and open source. The project supports its latest two minor releases, with each supported for roughly 12 months including maintenance.