It was Ikey Doherty's of Solus and Intel Clear linux fame passion project; was, because he basically left yet another project behind. Now it's being carried over by solus contributors and other interested parties who are working on making it a stable base for power users and distribution makers to use of.
It's basically build atop of a declative Nix/Guix-like package manager if it was made for a more sensibly readable config language like kdl, essentially toml but good, and it only deals in packages, not configs, simplifying it a lot, thus, you can just use as if it was a normal imperative package manager (it isn't) and just:
sudo moss pkg add whatever
And it'll declaratively update the config file to add the package to it, which you can just copy to another machine to replicate the current system's state, all without having to edit a config file in a language that requires some knowledge In functional programming, nor a degree in compsci to create a package for the distro. "System model" they call it.
As far I know, solus is intending to eventually use it as base. They pretty notoriously banned AI to their distro codebase a while back, definitely not slop.

