nix-inst (codeberg mirror) is an alternative to nix-env and nix profile written in rust. it prioritizes UX, stability, and performance.
it supports flakes, but does not require them. it removes several known failure modes of nix-env, while also fixing several issues with nix profile, and adding several features not present in either.
the project is still early in development, so i wouldn’t use it for anything critical, but it is stable enough i use it to manage my own user-level packages.