My comment is only a remark to "what holds back widespread Arc adoption".
If your goal is for arc to have widespread adoption then being able to leverage racket in a meaningful way will help get you there.
Currently the ability to drop into racket is not getting people to use arc, it still seems people would rather just use racket. http://arclanguage.org/item?id=20781
IMO, It would be better if arc had implicit methods that provide access to racket capabilities. In Clojure having libraries, name spaces, and a seamless interfaces to java translated into a plethora of libraries for Clojurians to utilize. Can we not do the same? Well if the goal is for "widespread adoption" then we need to.
