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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Parrot
Parrot (formerly Parrot Security OS) is a Debian-based, security-oriented distribution featuring a collection of utilities designed for penetration testing, computer forensics, reverse engineering, hacking, privacy, anonymity and cryptography. The product, developed by Frozenbox, comes with MATE as the default desktop environment.