>>18
It cant do things as simple as tail recursion optimizations
It can do tail recursion optimization, although loop/recur is a bit of a hack.
If clojure were implemented in C as most other compilers, than you have a more machine specific implementation to run on different platforms
Java, and by extension clojure, already runs on all major operating systems and a lot of phones so unless you meant running clojure on embedded systems I don't see the problem.