NixOS is a Linux distribution built on top of the Nix package manager. It uses declarative configuration and allows reliable system upgrades. Several official package “channels” are offered including current Stable release and Unstable following latest development. NixOS has tools dedicated to DevOps and deployment tasks.
NixOS is a trade-free operating system, except for the search engine in the firefox browser which uses google search. That’s a red flag as google collects all kinds of data, sells it to others and/or shows personalized ads. Therefore 4/5 blocks for NixOS.