Struggling to understand what Reactive Extensions are all about? This presentation aims to take a more practical approach at explaining reactive extensions, using data generated from Quadcopter drones on stage. We investigate streams and how they compose through filtering, mapping and merging. To compensate for the practical approach, at some point we introduce some meta-programming into the mix. Brains might blow up. Or get chopped to pieces by spinning propellers. Streams provide a natural way to model domains where events are generated over time, much like the real world. Streams also provide a simple interface for plugging things in and out, and therefore compose easily. They are a natural companion to a functional programming style. We attack this problem from three different angles. Bjørn Einar takes the practical hacker-dev approach, Einar looks at the problem from his Ivory Tower and Jonas provides the Strange Loop. Open your mind to a new style of programming. Your program might literally never be the same again.