NixOS
NixOS is an independently developed GNU/Linux distribution that aims to improve the state of the art in system configuration management. In NixOS, the entire operating system, including the kernel, applications, system packages and configuration files, are built by the Nix package manager.
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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.