I hope you're excited about Julia by now. The friendly, expressive, and intuitive syntax, the powerful read-eval-print loop (REPL), the great performance, and the richness of both built-in and third-party libraries are a game-changing combination for data science in particular—and programming in general. The fact that in just two introductory chapters we were able to grasp the basics of the language and configure a data science setup powerful enough to analyze the Iris dataset is quite amazing—congratulations, we've done a great job!

But we are literally just starting. The foundation we've laid is now strong enough to allow us to develop pretty much any kind of program using Julia. Hard to believe? Well, here's the proof—in the next three chapters, we'll develop a web-based game with Julia!

It will follow...