How far clojurescript is to be clojure/js. By that I mean how close the JVM and JS are semantically. There were discussions about that few months ago, because of differences deep down between platforms builtin types (js integers, etc). Swannodette also explained that cljs and clj don't share as much code as the team would like. How much clojure code would run correctly as-is on cljs ? Without having to use specific reader conditionals.