Portainer is described as 'Community Edition is a lightweight service delivery platform for containerized applications that can be used to manage Docker, Swarm, and Kubernetes environments. It is designed to be as simple to deploy as it is to use' and is a popular Docker Manager in the development category. There are more than 25 alternatives to Portainer for a variety of platforms, including Self-Hosted, Linux, Mac, Docker and Windows apps. The best Portainer alternative is Docker, which is both free and Open Source. Other great apps like Portainer are Arcane - Docker Management UI, Coolify, Cockpit Project and CapRover.
Cockpit is a SERVER manager, it manages a ton more than just Docker/Podman