I've been looking into Nix a lot lately (but have yet to take the leap - I'll probably start with devshell)

But a couple of projects have come up lately that piqued my interest wrt syntax and alteratives (Since I am not sure about Scheme anymore than Nix (as a langauge) :-)

  * https://github.com/maxmcd/bramble
  * https://nickel-lang.org/