Zero to Nix
On Nix's Language
NixOS and Flakes Book
NixOS in Production
Wombat’s Book of Nix
Contributing guidelines
Code of conduct
Wanted pages
Outreach
nixos.wiki outlines the rather bumpy history of NixOS wikis.
...or the contents of it. Currently, nixlang.wiki is automatically backed up to a git repository every five minutes.
This has the dual purpose of making it a little less centralized, and making it easier to read/write in your terminal.