For the core parts of Tvix we won't have any OS-specific dependencies, but each platform will need a working builder and sandbox implementation. I suspect that OpenBSD has at least one OCI-compatible sandboxing/containerisation method so it should end up running fine on there.

Nix itself is in first approximation "just a package manager", so not particularly tied to a kernel AFAIU. As to NixOS, this one's a Linux distro, so it currently mostly assumes Linux kernel AFAIK. I tried exploring plugging in L4Linux in that place, but failed due to not being able to understand related areas of NixOS/Nixpkgs well enough. Guix OS on the other hand has some (experimental?) support for GNU Mach kernel I believe.

> Nix itself is in first approximation "just a package manager"

I'd go even further: Nix is just a build tool, like Make.

In fact, it assumes far less about the system than Make; e.g. Make does all sorts of shell-related things, whilst Nix simply executes a binary (with a list of arguments and a set of env vars).

(Nixpkgs definitions almost always use a bash binary as their executable, so it feels more like Make; but Nix doesn't care)

Guix System (the full OS distribution) supports both Linux and GNU Hurd as kernels

Ouch, right, I borked the name of the GNU kernel - sorry and thanks!

Linux and OS X are officially supported

https://nixos.org/manual/nix/stable/installation/supported-p...