I can't speak of the biggest obstacles but Clojure was bound to the JVM pretty early (hence the j) -- I personally have no real interest in getting off the JVM

I can't speak of the biggest obstacles but Clojure was bound to the JVM pretty early (hence the j) -- I personally have no real interest in getting off the JVM so I have not followed it close at all. Bootstrapping would be the obvious answer though.