this is pretty cool. it’s a tutorial with interactive exercises that explores the Nix language as a general-purpose functional programming language, outside of its role as the configuration and package definition language for NixOS. understanding Nix better as a language makes more complicated packages easier to write (and is necessary to understand the guts of nixpkgs and the parts of Nix written in itself), but it also has a number of unique advantages as a programming language within a very specific domain.