Nickel is a generic configuration language, heavily inspired by Nix but adding a number of features such as a gradual type system and a built-in merge system for records. This in turn allows for a better developer experience (error reporting, powerful LSP server, introspectability), more runtime guaranties, and eventually better performances (since there's no need to encode a computationally costly module system into it).

Nixel is an experimental Nickel library allowing to use Nickel for writing Nix configurations. This makes it possible to leverage the niceties of the language for writing modular and user-friendly configurations.