Nixpkgs
Nixpkgs 是最大的 Nix 軟體包儲存庫和 NixOS 模組。儲存庫 託管在 GitHub 上 並且由社群維護，另外還有 NixOS Foundation 的官方支持。
尋找可用的套件和選項，請看 尋找套件。
如同在 NixOS 21.05 釋出 發布會 所強調的，"NixOS 已經被認為是 最即時更新的發行版 和 第三多軟體包的發行版。" 這歸功於社群的持續貢獻使 Nixpkgs 成為最重要且最強大的 Linux 軟體包儲存庫。
子頁面
這裡有一系列的文章關於操作 nixpkgs：
Releases
The packages and modules hosted on Nixpkgs are distributed through various channel branches intended for particular use-cases. In practice they are differentiated by the level of testing updates must pass on the official nixos.org Hydra instance and the number of updates they receive.
For NixOS users, nixos-unstable channel branch is the rolling release, where packages pass build tests and integration tests on a VM, and are tested from the perspective of being an operative system (this means things like the X server, KDE, various servers, and lower level details like installing bootloaders and running the NixOS installation steps are also tested).
For standalone Nix users, nixpkgs-unstable channel branch is the rolling release, where packages pass only basic build tests and are upgraded continuously.
Both NixOS and Nix users can use stable channel branches - the latest being nixos-23.11 - to receive only conservative updates for fixing critical bugs and security vulnerabilities. Stable channel branches are released bi-annually at the end of May and the end of November.
Using stable channels on NixOS is comparable to the user experience on other Linux distributions.
Alternatives
Due to the fact that Nixpkgs is only a Nix expression, it is possible to extend or replace the logic with your own sources. In fact, there are a number of extensions as well as complete replacements for Nixpkgs, see the Alternative Package Sets article.