It's cool to see how all these little examples are run for a variety of languages -- which most devs haven't used. A Clojure example would have been really slo

It's cool to see how all these little examples are run for a variety of languages -- which most devs haven't used. A Clojure example would have been really slow because Clojure adds even more slowness to the already incredibly slow JVM startup time (big Clojure fan here btw). But it's nothing new: we know that Java, for example, totally and utterly sucks at scripting and there's a reason why scripts commonly piped on Unx systems aren't written in Java. You still can* do some scripting in Java (or Ruby for that matters) but you have to keep in mind that it's going to be really slow. And, yes, startup time for scripts does matter: once again there's a reason why small utils regularly piped are typically written in languages allowing fast startup time.