A lot of exciting changes and improvements landed in the NixOS 17.03, which comes as a replacement for the NixOS 16.09 update that some of you out there might be using on your personal computers. First of all, NixOS 17.03 updates the nixpkgs component to be extensible through overlays. This makes it possible to mark packages in nixpkgs as non-secure through listed vulnerabilities. Furthermore, the development team managed to rewrite the overridePackages function to be replaced by overlays, as well as the cross compilation functionality.