So far, we've already taken a big step forward in Play! Framework 2 by covering high-level concepts, and also introduced more advanced ones in some cases.

We tackled a whole and definitive installation of the framework itself, but with all of the other things that make a development environment: machine, IDE, command-line tool, and so on.

We've also covered the basics that are common to all the Play! 2-based web applications: Java and Scala controllers, actions, and even a bit of views.

We took the opportunity to see the whole machinery in action, and made some adaptations showing us the coolest features provided by Play! 2, such as compilation on the fly and errors shown on the browser side.

At this stage, we know that Scala is the core language of the system; moreover, it's also the templating system's language. So in the next chapter, we'll see just enough Scala to write great templates that are easy to create and maintain.