[ffuugoo]

I'd not compare Nix to other three. Yes, you are right, it is kind of "distro-agnostic/sandboxed/multiple-versions", it "need to install to a root directory" and does not "need a runtime daemon", but otherwise it is totally different and much more than others.

[chriswarbo]

I mostly agree, but there is a similarity in that the Nix build/CI server "Hydra" puts a "One click install" link on build outputs (e.g. http://hydra.nixos.org/build/47550492 )