In this presentation you will see why Reactive Extensions (Rx) is a powerful technology for asynchronous stream processing. RTI Data Distribution Service (DDS) will be used as the source of data and as a communication channel for asynchronous data streams. On top of DDS, we'll use Rx to subscribe, observe, project, filter, aggregate, merge, zip, and correlate one or more data streams (Observables). The live demo will be very visual as bouncing shapes of different colors will be transformed in front of you using C# lambdas, Rx.NET, and Visual Studio. You will also learn about the new Rx4DDS.NET library that integrates RTI DDS with Rx.NET. Rx and DDS are a great match because both are reactive. Rx is based on the subject-observer pattern, which is quite analogous to the publish-subscribe pattern of DDS. When used together they support distributed dataflows seamlessly. If time permits, we will touch upon advanced Rx concepts such as stream of streams (IGroupedObservable) and how it captures DDS "keyed topics". The DDS applications using Rx4DDS.NET dramatically simplify concurrency to the extent that it can be simply configured.