NixNG
A GNU/Linux distribution, similar to NixOS with the main distintion beings its simpler design, akin to BSDs and Void Linux. It replaces SystemD with runit and in the future OpenRC, this allows for much lighter systems, which are suitable for running in containers.
ra-containers
Nix built, fully declarative and configurable container images. They are similar in function to the official Docker container images and have similar APIs therefore are a convenient replacement for your existing images, if you need more Nix in your life.