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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ChromeOS Flex
ChromeOS Flex, developed by Google, is a free and lightweight Linux distribution based on Gentoo-derived ChromeOS. Unlike ChromeOS which is designed specifically for Chromebook computers, ChromeOS Flex can be installed on most x86_64 devices with a AMD or Intel processors, offering a Chromebook-like experience.