# Overview {#preface}

Nixpkgs is a set of packages for the [Nix package manager](https://nixos.org/nix/), released under the [MIT license](https://github.com/NixOS/nixpkgs/blob/master/COPYING).

Further documentation:

- [nix.dev](https://nix.dev/): Tutorials and guides for getting things done with Nix
- [NixOS Search](https://search.nixos.org)
- [Contributing](https://github.com/NixOS/nixpkgs/blob/master/CONTRIBUTING.md): to Nixpkgs

Nix expressions describe how to build packages from source and are collected in
the [nixpkgs repository](https://github.com/NixOS/nixpkgs).

Packages are distributed through [channels](#how-channels-work).