RxJS Tutorial from Codingcompiler. RxJS is a responsive programming library that uses Observables to make writing asynchronous or callback-based code easier. This project is a rewrite of Reactive-Extensions/RxJS (RxJS 4) with better performance, better modularity, better debug call stack, while maintaining most backwards compatibility, with only some destructive changes. (breaking changes) is to reduce the outer layer of the API.