Webmin is a web-based system configuration tool for Unix-like systems, although recent versions can also be installed and run on Windows.
Authentik is an open-source Identity Provider focused on flexibility and versatility. You can use Authentik in an existing environment to add support for new protocols, implement sign-up/recovery/etc. in your application so you don't have to deal with it, and many other things.
Portainer is a simple management solution for Docker. Easily manage your Docker hosts and Docker Swarm clusters via Portainer web user interface.
Pi-hole is a Linux network-level advertisement and internet tracker blocking application which acts as a DNS sinkhole, intended for use on a private network.
openmediavault is the next generation network attached storage (NAS) solution based on Debian Linux.