# jruby/jruby

JRuby, an implementation of Ruby on the JVM

Repository: https://github.com/jruby/jruby
Canonical: https://ross.abutalabs.com/products/jruby
Homepage: https://www.jruby.org
Language: Ruby
License: NOASSERTION
License Family: other
Topics: jruby, ruby-language, jvm, ruby, invokedynamic, concurrency, performance
Last push: 2026-08-26T20:44:20+00:00

## Health v2 (maintenance only)
Score: 97/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 94, longevity 100
- inputs: {"age_days": 6359, "days_push": 7, "days_rel": 42, "gap_med": 29, "n_releases_24m": 18}
- 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 3915, forks 946 (observed 2026-08-28T04:08:28.920035+00:00)

## What it is
JRuby is an implementation of the Ruby programming language that runs on the Java Virtual Machine. It offers true parallelism without a global interpreter lock, tight Java interoperability, and can be embedded as a scripting language in Java applications.

## Use cases
- run ruby on the jvm
- faster ruby implementation
- use java libraries from ruby
- embed ruby scripting in a java application
- true multithreaded ruby without gil
- run rails on the jvm

## When to choose
- you want Ruby performance and real parallel threads on the JVM
- you need to call Java classes or embed Ruby inside Java apps
- you want platform-independent Ruby deployment with a JRE 21+

## When to avoid
- you need C-extension gems that rely on MRI's native API
- you have no JVM available or want a minimal runtime footprint
- you depend on the very latest Ruby features before JRuby adds compatibility

## Facets
- artifact type: cli-tool
- maturity: active
- function: interpreter, programming-language, concurrency, developer-tools
- domain: programming-languages, cross-platform, developer-tools
- platform: jvm, cross-platform, windows, cli
- tags: ruby, jruby, jvm-language, language-implementation, java-interop, no-gil, parallelism, jvm, linux, macos

## Member repositories
- jruby/jruby (main) score 97

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:28.920035+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 2026-08-29T18:25:03.402200+00:00, confidence not recorded.
  - readme: https://github.com/jruby/jruby (fetched 2026-08-28T04:08:28.920035+00:00, sha 2148a47cae90)
  - homepage: https://www.jruby.org (fetched 2026-08-29T09:18:55.994319+00:00, sha 38e3b225074f)
  - site_page: https://www.jruby.org/getting-started (fetched 2026-08-29T09:18:56.003583+00:00, sha fa3fb1364cd5)
  - site_page: https://www.jruby.org/documentation (fetched 2026-08-29T09:18:56.005468+00:00, sha c09cfe7ab941)
- Data as of 2026-08-30T08:39:29.467469+00:00.