# Reactive-Extensions/RxJS

The Reactive Extensions for JavaScript

Repository: https://github.com/Reactive-Extensions/RxJS
Canonical: https://ross.abutalabs.com/products/reactive-extensions-rxjs
Homepage: http://reactivex.io
Language: JavaScript
License: NOASSERTION
License Family: other
Archived: true
Last push: 2018-04-18T20:17:39+00:00

## Health v2 (maintenance only)
Score: 10/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 8, longevity 100
- inputs: {"age_days": 5353, "days_push": 3059, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: archived, no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 19339, forks 2056 (observed 2026-08-28T04:11:27.655374+00:00)

## What it is
The Reactive Extensions for JavaScript (RxJS 4) is a library for composing asynchronous and event-based programs using observable sequences, operators, and schedulers. This original Reactive-Extensions repository is legacy and has been superseded by the actively maintained reactivex/rxjs project.

## Use cases
- compose async event streams in javascript
- handle ui events with observables
- debounce and combine ajax responses
- manage complex asynchronous data flows
- convert callbacks into observable streams
- learn reactive programming in javascript

## When to choose
- maintaining a legacy codebase already using the rx 4.x package
- studying the original RxJS implementation and its operator set
- working in an environment pinned to the old rx npm package

## When to avoid
- starting a new project - use the modern reactivex/rxjs (rxjs 7+) instead
- you need TypeScript support or current maintenance
- you need up-to-date documentation and community support

## Facets
- artifact type: library
- maturity: abandoned
- function: state-management, concurrency, developer-tools
- domain: web-development, frontend
- platform: browser, cross-platform
- tags: rxjs, observables, reactive-extensions, event-streams, functional-programming, legacy, superseded, javascript, reactive-programming, nodejs

## Member repositories
- Reactive-Extensions/RxJS (main) score 10

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:11:27.655374+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T17:00:15.532134+00:00, confidence not recorded.
  - readme: https://github.com/Reactive-Extensions/RxJS (fetched 2026-08-28T04:11:27.655374+00:00, sha 34f86509b2c9)
  - homepage: http://reactivex.io (fetched 2026-08-29T07:58:53.157908+00:00, sha 82cef0299f27)
  - site_page: https://reactivex.io/documentation/observable.html (fetched 2026-08-29T07:58:53.166977+00:00, sha 9a5601c77b6d)
  - site_page: https://reactivex.io/documentation/operators.html (fetched 2026-08-29T07:58:53.169306+00:00, sha a0acd380d044)
  - site_page: https://reactivex.io/documentation/single.html (fetched 2026-08-29T07:58:53.172217+00:00, sha 5cb896bf348b)
  - site_page: https://reactivex.io/documentation/subject.html (fetched 2026-08-29T07:58:53.176273+00:00, sha 4aee216f65c4)
  - site_page: https://reactivex.io/documentation/scheduler.html (fetched 2026-08-29T07:58:53.179343+00:00, sha 12a5c3e9ebce)
- Data as of 2026-08-30T08:39:29.467469+00:00.