# eventmachine/eventmachine

EventMachine: fast, simple event-processing library for Ruby programs

Repository: https://github.com/eventmachine/eventmachine
Canonical: https://ross.abutalabs.com/products/eventmachine
Language: Ruby
License: NOASSERTION
License Family: other
Last push: 2026-07-24T05:03:45+00:00

## Health v2 (maintenance only)
Score: 65/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 94, release rhythm 8, longevity 100
- inputs: {"age_days": 6590, "days_push": 40, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 4277, forks 633 (observed 2026-08-28T04:08:41.092829+00:00)

## What it is
EventMachine is an event-driven I/O and lightweight concurrency library for Ruby based on the Reactor pattern. It enables building highly scalable network servers, asynchronous clients, and proxies without complex threaded network programming.

## Use cases
- build a scalable event-driven server in Ruby
- write asynchronous HTTP clients for REST APIs
- create efficient network proxies with custom logic
- monitor files and networks reactively
- implement custom network protocols in Ruby
- build real-time messaging or chat servers

## When to choose
- you need high-performance event-driven I/O in Ruby
- you're building servers, proxies, or async clients on the Reactor pattern
- you need cross-platform support including Windows and JRuby
- you want a mature, battle-tested library

## When to avoid
- you're using modern async/await Ruby code with the async gem ecosystem
- your use case is simple synchronous I/O without concurrency needs
- you prefer Fibers or Ractors-based concurrency models

## Facets
- artifact type: library
- maturity: stable
- function: concurrency, networking, http-server, websocket
- domain: networking, developer-tools, backend
- platform: ruby, cross-platform, windows
- tags: reactor-pattern, event-driven-io, async, ruby-gem, linux, macos

## Member repositories
- eventmachine/eventmachine (main) score 65

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:41.092829+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 2026-08-29T18:21:59.883950+00:00, confidence not recorded.
  - readme: https://github.com/eventmachine/eventmachine (fetched 2026-08-28T04:08:41.092829+00:00, sha e60e224317f1)
- Data as of 2026-08-30T08:39:29.467469+00:00.