Guix

Like NixOS a PackageManagementTool / repository for building reliable and immutable operating systems from scratch.

Unlike NixOS, Guix is from GNU, uses GuileScheme to specify packages (rather than a custom declarative language) and is focused on pure FreeSoftware packages

https://en.wikipedia.org/wiki/GNU_Guix

http://guixwl.org/

https://news.ycombinator.com/item?id=18908591