Flox is a virtual environment and package manager designed to facilitate the creation, sharing, and management of portable environments. It leverages nixpkgs, the largest open-source repository, containing over 80,000 packages. Flox aims to bring consistency and reproducibility to the software development lifecycle, addressing the challenge of managing a dynamic set of tools, frameworks, and packages. Originating from the deployment of Nix at the D. E. Shaw group, it has proven invaluable in simplifying Nix for newcomers and providing centralized package control.