# openjdk/loom

https://openjdk.org/projects/loom

Repository: https://github.com/openjdk/loom
Canonical: https://ross.abutalabs.com/products/openjdk-loom
Language: Java
License: GPL-2.0
License Family: copyleft
Topics: openjdk, java, jvm, loom
Last push: 2026-08-22T10:18:13+00:00

## Health v2 (maintenance only)
Score: 77/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 99, release rhythm 35, longevity 100
- inputs: {"age_days": 2694, "days_push": 11, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 2014, forks 255 (observed 2026-08-28T04:06:05.383706+00:00)

## What it is
Project Loom is the OpenJDK project that developed lightweight concurrency for the Java platform, most notably virtual threads (fibers) and structured concurrency. This repository is a JDK development fork where the Loom features were implemented before being integrated into mainline OpenJDK releases.

## Use cases
- run millions of lightweight concurrent tasks in Java
- write blocking-style code that scales like async
- adopt virtual threads for high-throughput servers
- use structured concurrency to manage task lifetimes
- migrate thread-per-request Java services without reactive complexity
- experiment with continuations on the JVM

## When to choose
- you need massive concurrency in Java without rewriting to async/reactive styles
- you want to test or contribute to JVM-level virtual thread development
- your server handles many concurrent blocking I/O operations

## When to avoid
- you need a stable production JDK - use a mainline OpenJDK release instead
- you work in a non-JVM language
- you need CPU-bound parallelism only - traditional thread pools suffice

## Facets
- artifact type: library
- maturity: active
- function: concurrency, interpreter, developer-tools
- domain: programming-languages, developer-tools, microservices
- platform: jvm, windows
- tags: virtual-threads, jvm, openjdk, project-loom, lightweight-concurrency, continuations, linux, macos

## Member repositories
- openjdk/loom (main) score 77

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:06:05.383706+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 2026-08-30T03:00:50.105911+00:00, confidence not recorded.
  - readme: https://github.com/openjdk/loom (fetched 2026-08-28T04:06:05.383706+00:00, sha 50b0ca29cd76)
- Data as of 2026-08-30T08:39:29.467469+00:00.