zlacker

It's a bit hidden in their about page:

    GNU Guix provides state-of-the-art package management features such as transactional upgrades and roll-backs, reproducible build environments, unprivileged package management, and per-user profiles. It uses low-level mechanisms from the Nix package manager, but packages are defined as native Guile modules, using extensions to the Scheme language—which makes it nicely hackable.

https://guix.gnu.org/en/about/

>>ddella+(OP)
If I understand correctly, they're saying that the low level stuff works the way it works in Nix, not that they use Nix for that.

I am aware Guix did fork Nix but from what I've read, there's almost nothing left in Guix that still uses the initial Nix code?

>>brabel+Nf
I am extremely out of the loop, but I believe until somewhat recently it still used nix-daemon and the corresponding drv format, but it may have since been rewritten.