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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Solus
Solus is a Linux distribution built from scratch. It uses a forked version of the PiSi package manager, maintained as "eopkg" within Solus, and its flagship edition uses the Budgie desktop environment.