Comment by wrxd

I also really like that Nix (both on NixOS or as a package manager for Linux/macOS) can temporarily fetch packages with `nix shell` removing entirely the need to install something I am just trying out or something I know I am not going to need on a regular basis.

Similarly the integration of flakes/devshells and direnv is great to create reproducible development environments. Everything I need and at the correct versions are automatically setup as soon as I `cd` into a project directory.