Nitrux
Nitrux is a desktop Linux distribution built from Debian, but with an immutable base system, the OpenRC init system, and without any traditional Debian package management tools. It uses the Calamares system installer and includes the Hyprland window manager, Hypr utilities, the greetd+QtGreet login manager, and the Waybar Wayland bar.
SmartOS
SmartOS is an open-source UNIX-like operating system based on illumos, a community fork of OpenSolaris. It features four technologies - ZFS (a combined file system and logical volume manager), DTrace (a dynamic tracing framework for troubleshooting kernel and application problems), Zones (a lightweight virtualisation solution), KVM and bhyve (two full virtualisation solutions for running a variety of guest operating systems, including Linux, Windows, BSD and Plan9).