The thing that is special about Nix the language is everything it doesn't have (no side effects[1], no state, no mutability). It's a very small and simple langu

The thing that is special about Nix the language is everything it doesn't have (no side effects[1], no state, no mutability). It's a very small and simple language. Those constraints are really important for the rest of the Nix ecosystem to work. [1]: technically there is one side effect - putting a derivation (i.e. a recipe for how to build a package) into the nix store.