Reactive Programming is a hot topic as of late, especially with such things as the Reactive Manifesto. Applications' needs have changed over time, from simple polling for data to a full reactive system where data is pushed at you. Each time, we're adding more complexity, data, and asynchronous behavior to our applications. How do we manage it all? How do we scale it? By moving towards "Reactive Architectures" which are event-driven, resilient, and responsive. With the Reactive Extensions, you have all the tools you need to help build these systems.The Reactive Extensions for Ruby (RxRuby) is a set of libraries for composing asynchronous and event-based programs using observable sequences and fluent query operators that many of you already know in Ruby. Using RxRuby, developers represent asynchronous data streams with Observables, query asynchronous data streams using our many operators, and parameterize the concurrency in the asynchronous data streams using Schedulers. Simply put, RxRuby = Observables + Operators + Schedulers.