See your server in a web browser and perform system tasks with a mouse. It’s easy to start containers, administer storage, configure networks, and inspect logs. Full dashboard. Lets you configure things as well as look in on them. Extensible with a plugin architecture. Packaged in many distros, including Debian. Does not replace the shell, does not take over the system's configuration so you can work from both ends and they won't conflict. Doesn't step on other management apps, either. Uses your account, relies on sudo to elevate privs. Mobile friendly. If you can reach it using SSH, you can admin it.
Github: https://github.com/cockpit-project/cockpit
Appears to be written in C.