RxJS

RxJS (Reactive Extensions for JavaScript) is a powerful library for reactive programming using observables that makes it easier to compose asynchronous and event-based programs. The library provides a collection of operators that allow developers to transform, filter, combine, and manage streams of data over time. RxJS is particularly effective for handling complex asynchronous scenarios like HTTP requests, user input events, WebSocket connections, and animations. It implements the Observable pattern along with Iterator and functional programming concepts to provide a unified approach to managing asynchronous data flows. RxJS is heavily used in Angular applications (included by default) but is framework-agnostic and can be used with React, Vue, or vanilla JavaScript. The library helps manage issues like race conditions, memory leaks, and callback hell through declarative stream composition. Common operators include map, filter, mergeMap, switchMap, debounceTime, and combineLatest for sophisticated data transformation pipelines.