ClojureScript's promise is to bring the expressiveness and agility of the Clojure programming language to JavaScript developers. Having such power at hands means that teams working on single page applications—and on Node.js services as well—more productivity and less frustration.

But to be able to take complete advantage of this platform, we must grasp its inner mechanisms and, sometimes patiently, work our way towards the perfect ClojureScript live-coding environment. In this chapter, we'll cover the material necessary to achieve this objective.

We'll begin by studying the ClojureScript ecosystem, focusing on its compiler internals and talking about the Read-Eval-Print-Loop (REPL) it offers. We'll then present some alternative building blocks that make it possible to expose interactive ClojureScript development work-flows through third-party tools. We'll finally leverage all of this knowledge in order to build full-fledged, integrated, and interactive ClojureScript development environments. To get started with adopting this approach, we'll discuss the following: