RxJS with Angular 101 RxJS is a library for reactive programming using Observables, to make it easier to compose asynchronous or callback-based code. Angular and Angular Material implements RxJS out of the box. Other Javascript libraries can use RxJS also but have to install it like a package. Official documentation can be found on RxJS. Since the documentation is quite complicated and as the RxJS library is very large, this article will cover the most important concepts used on daily basis. in Development > Angular and Ionicwith 101angulardocumentationobservablesrxjstutorial