NixOS
NixOS is a Linux distribution built on the Nix package manager, a purely functional package and configuration system. The whole operating system – kernel, packages, services and settings – is described declaratively in a single configuration.nix file and rebuilt with nixos-rebuild switch. Because every component lives in an immutable, hash-addressed store, systems are reproducible to the byte, upgrades are atomic, and rollbacks are a reboot away.
Key Features
- Declarative configuration – describe the entire system in one file; NixOS makes it so rather than you hand-editing scattered configs
- Reproducible builds – the same configuration and nixpkgs revision builds identical systems, eliminating config drift
- Atomic upgrades – switching generations never leaves a half-installed state; if an update breaks, boot a previous generation to roll back
- Immutably isolated store – every package and version lives side-by-side in /nix/store, so dependency conflicts cannot occur
- Easy rollback – the boot menu lists all system generations, so returning to a working state is straightforward
- Multi-user and risk-free – users can install packages via Nix profiles without root, and nothing global is ever clobbered
- Huge package collection – Nixpkgs packages thousands of programs, with declarative service modules for common daemons
- Dual release model – stable releases twice a year, plus a fast-moving unstable channel
Why Use NixOS?
NixOS turns system administration into version-controlled, reproducible engineering. For developers and server operators who want identical environments everywhere – dev laptops, CI builders, cloud hosts – it removes drift and makes rollbacks trivial compared with traditional distributions.
Use Cases
- Reproducible development environments that match production exactly
- Servers and cloud infrastructure managed entirely as code
- People who want to experiment freely, knowing any change can be rolled back
- Advanced users who appreciate declarative, functional system design
Platform
Linux (x86-64, AArch64)
Licence
Free and open source. The NixOS distribution and Nix ecosystem are released under the MIT licence, with bundled software (such as the Linux kernel under GPL-2.0) keeping its own licences.