What is Reactive Programming?

Reactive Programming is a term that's gaining more and more recognition in the IT community. As we will see in this chapter, it is not a new topic and has been sadly overlooked for many years. Recent advancements in hardware and software, combined with applications requiring more elaborate user interactions, have resulted in the concept of Reactive Programming being rediscovered by a wider audience. Reactive Programming is both an overloaded term and a broad topic. As such, this book will focus on a specific formulation of Reactive Programming called Compositional Event Systems (CES).

In this chapter, we will cover the following topics:

• A working example of a reactive application in Clojure
• The history of Reactive Programming
• The most common terms in Reactive Programming
• The most common applications of Reactive Programming