[costrouc]

There is a quite mature configuration language nix that is behind nixpkgs, nixos, and many other projects. Worth checking out for others here that are interested in abstractable configuration langauges. It is a functional lazily evaluated language.

[pblkt]

Nix is dynamically typed. This shows badly in its discoverability and validation stories.

The ecosystem is fantastic, but it's hard to make the case to migrate an existing configuration to it for the sake of using nix.

Dhall is another option in this space, BTW. It has other faults that score CUE existence points, thought.

[cwp]

I've been wondering if CUE's graph unification idea could be used as a type system for Nix. It might be hard to square with the way nix does overlays and overrides. It's a very common thing to take some existing derivation and produce a tweaked version. That might not work with graph unification.