Clojurescript is the more "all the way down" of the two. It managed to self-host a few months ago so in theory you could write a backend and cross compile to your computing platform of choice. I know of a number of alternative targets but they all predate the self-hosting and none are actively maintained:

[1] https://github.com/takeoutweight/clojure-scheme [2] https://github.com/raph-amiard/clojurescript-lua

I think it'd be a fun project to get cljs-lua working and build a system for developing OpenResty apps but it's so low on my priority list I don't anticipate ever making it happen.