GNU Guix 1.0.0 has been released [gnu.org]. The big 1.0 is an important milestone for most Free Software. In this case it is the result of seven years of development. GNU Guix is a general toolbox for software deployment, also known as a package manager, but with advancements over RPM and APT, which it can co-exist with. However it can also be used as a complete distro.
In addition to standard package management features, Guix supports transactional upgrades and roll-backs, unprivileged package management, per-user profiles, and garbage collection. When used as a standalone GNU/Linux distribution, Guix offers a declarative, stateless approach to operating system configuration management. Guix is highly customizable and hackable through Guile programming interfaces and extensions to the Scheme language.