parallel require

scratch.clj

(alter-var-root #'require
                (fn [o-require]
                  (fn [& args]
                    (let [{opts true nses false} (group-by keyword? args)]
                      (doall
                       (map #(.join %)
                            (doall
                             (for [ns nses]
                               (doto (Thread. #(apply o-require ns opts))
                                 .start)))))))))