RxJS allows you to create observable streams from DOM Events, XHR, Promises, Node callbacks, Arrays, and Maps
ReactiveX is a combination of the best ideas from the Observer pattern, the Iterator pattern, and functional programming.
ReactiveX is more than an API, it’s an idea and a breakthrough in programming. It has inspired several other APIs, frameworks, and even programming languages.
View the RxJS docs on Github or checkout the main ReactiveX web site, reactivex.io