NixOS is a Linux distribution built entirely on the Nix package manager, where the whole system (kernel, packages, services, and configuration) is declared in a single set of files. Upgrades are atomic and fully reproducible rollbacks are a built-in feature.
NixOS
nixos.org
Our take
NixOS takes the reproducibility idea further than any other mainstream distro: you can commit your system config to a repo and rebuild an identical machine elsewhere, which is a real privacy and security advantage because accidental drift is impossible. The Nixpkgs collection is among the largest of any package manager. The learning curve is steep (the Nix language and its functional approach to configuration are genuinely unfamiliar territory), and some proprietary software or closed-source drivers require extra effort. The right choice for technically curious users who want a fully auditable, reproducible system and are prepared to invest time upfront.
GitHub at a glance
NixOS/nixpkgs
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25,183
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Last commit
today
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License
MIT
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NixOS alternatives
Qubes OS Qubes OS: A reasonably secure operating system
Tails Tails: Portable, encrypted and secure through the Tor network
Whonix A free, open-source desktop operating system that forces all traffic through Tor, run as two isolated virtual machines.
secureblue secureblue is a security-hardened immutable Linux OS built on Fedora Atomic Desktops. It ships as OCI bootable container images and applies kernel hardening, a hardened memory allocator from GrapheneOS, and a hardened Chromium browser called Trivalent.
Kicksecure Kicksecure is a security-hardened Debian-based Linux distribution that applies a broad set of kernel and userspace hardening settings out of the box, reducing the attack surface without requiring manual configuration. It also serves as the foundation for the Whonix anonymity OS.
Fedora Atomic Desktops Fedora Atomic Desktops (Silverblue, Kinoite, and others) are immutable Fedora variants where the base OS is read-only and updated atomically via rpm-ostree. Applications run as Flatpaks, and rollback to a prior OS image is built in.
NixOS license, in plain English
MIT Permissive
Do almost anything: use, change, and ship it, even inside closed-source products. The only condition is keeping the copyright notice.
Permits
- Commercial use
- Modification
- Distribution
- Private use
Requires
- License and copyright notice
Does not provide
- Liability cover
- Warranty
Why it matters: Permissive licensing lets anyone reuse this, including inside closed products. That is freedom to build on, but no guarantee that downstream copies stay open.
Plain-language summary of the project's license, not legal advice. Read the full text for the exact terms.