# bellard/mquickjs

Public repository of the Micro QuickJS Javascript Engine

Repository: https://github.com/bellard/mquickjs
Canonical: https://ross.abutalabs.com/products/mquickjs
Language: C
License: NOASSERTION
License Family: other
Last push: 2026-06-04T14:29:00+00:00

## Health v2 (maintenance only)
Score: 54/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 85, release rhythm 35, longevity 18
- inputs: {"age_days": 254, "days_push": 90, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases, no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 6130, forks 238 (observed 2026-08-28T04:09:36.358263+00:00)

## What it is
MicroQuickJS is a compact JavaScript engine written in C, derived from QuickJS, designed for embedded systems with as little as 10 kB of RAM and ~100 kB of ROM. It supports a strict-mode subset of JavaScript close to ES5 and includes a REPL (mqjs) with bytecode compilation for offline execution.

## Use cases
- run javascript on microcontrollers with 10 kB of ram
- embed a javascript interpreter in a c application
- precompile javascript to bytecode for embedded devices
- evaluate scripts on resource-constrained iot hardware
- sandbox small scripts with strict memory limits
- run a javascript repl on an embedded board

## When to choose
- you need a tiny, fast JavaScript engine for embedded or memory-constrained targets
- you want bytecode precompilation to save ROM and startup time
- you prefer a stricter ES5-like subset that still runs on other engines
- you want a tracing GC and stackless VM for predictable memory use

## When to avoid
- you need full modern ES6+ JavaScript features
- you need high compatibility with browser or Node.js ecosystems
- you want a mature, permissively licensed engine without license ambiguity
- you need top-tier JIT performance for compute-heavy workloads

## Facets
- artifact type: library
- maturity: active
- function: interpreter, compiler, programming-language, embedded
- domain: programming-languages, embedded-systems, developer-tools
- platform: embedded, windows, c, cli
- tags: javascript-engine, es5-subset, tracing-garbage-collector, bytecode, low-memory, quickjs, iot, linux, macos

## Member repositories
- bellard/mquickjs (main) score 54

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:09:36.358263+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 2026-08-29T17:47:58.370116+00:00, confidence not recorded.
  - readme: https://github.com/bellard/mquickjs (fetched 2026-08-28T04:09:36.358263+00:00, sha 4a74a8defbf3)
- Data as of 2026-08-30T08:39:29.467469+00:00.