Chapter 9 contains a short discussion of future trends we’re seeing in DSL-based development. Functional programming is becoming more popular, because functional abstractions offer better composability than the corresponding OO ones. I expect lots of DSL development to mature in the functional programming world. Techniques like parser combinators will become more popular as developers start appreciating their real power. Another area that’s expanding is DSL workbenches, which offer a complete development and maintenance stack for DSLs. In this part of the book I also discuss the important topic of DSL versioning and some of the practices that you can adopt to ensure a smooth evolution of the DSL syntax for your users. The main thrust of part 3—chapter 9—is to touch base on these developing trends in the DSL world.