This is your one stop shop introduction to get oriented to the world of reactive programming. There are lots of such intros out there even manifestos. We hope this is the one where you don't get lost and it makes sense. Get a definition of what "reactive" means and why it matters. Learn about Reactive Streams and Reactive Extensions and the emerging ecosystem around them. Get a sense for what going reactive means for the programming model. See lots of hands-on demos introducing the basic concepts in composition libraries using RxJava and Reactor.