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.
VS
Synex
Synex is a GNU/Linux distribution based on Debian's "Stable" branch, developed with the official Debian Live Build tool. It offers four separate desktop options with GNOME, LXDE, KDE Plasma and Xfce, all of which are composed of a rather frugal set of applications in its default state, without any development tools or offices suites.