I imagine everything said in the article also applies to the Nix package manager[0]. One of its nice features is the Nix expression language (aka Nix) [1]. It has an elegant mixture of purity and pragmatism. I imagine guile scheme would have a lot more integration opportunities outside of just system/build/configuration management. It'd be interesting to see Guix expressions that actually mix other scheme libraries or concepts, rather than just taking Nix expressions and removing the syntax.
I very much like how Guix is just a Guile Scheme library and can itself be integrated with other Scheme code. There is, for example, guix-web, a web interface to the package manager; there also is an Emacs interface using geiser.
Using Guile has turned out to be a great feature in itself and it is still fueling the development of new features that otherwise would be awkward to implement, such as the new "guix graph" command to visualise dependencies.
>It'd be interesting to see Guix expressions that actually mix other scheme libraries or concepts, rather than just taking Nix expressions and removing the syntax.
We already do this. Our build scripts are written in Guile, not Bash like in Nix, and they take advantage of Guile's standard library which has things like a pattern matcher, an HTTP client and server, a POSIX interface, a foreign-function interface, an XML parser, etc. We use third-party libraries such as guile-json and guile-charting in some of our tools, as well.
[0]: http://nixos.org/nix/ [1]: http://nixos.org/nix/manual/#chap-writing-nix-expressions