If you´ve seen how dozens of lines of Java or Ruby can dissolve into just a few lines of Clojure, you´ll know why the authors of this book call it a ´´joyful language´´. Clojure is a dialect of Lisp that runs on the JVM. It combines the nice features of a scripting language with the powerful features of a production environment -features like persistent data structures and clean multithreading that you´ll need for industrial-strength application development.