# fengari-lua/fengari

🌙 φεγγάρι - The Lua VM written in JS ES6 for Node and the browser

Repository: https://github.com/fengari-lua/fengari
Canonical: https://ross.abutalabs.com/products/fengari
Language: JavaScript
License: MIT
License Family: permissive
Topics: lua, javascript, es6, vm, fengari, lua-vm
Last push: 2026-01-02T13:02:57+00:00

## Health v2 (maintenance only)
Score: 58/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 60, release rhythm 31, longevity 100
- inputs: {"age_days": 3500, "days_push": 243, "days_rel": 250, "gap_med": null, "n_releases_24m": 1}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 2026, forks 85 (observed 2026-08-28T04:06:06.881871+00:00)

## What it is
Fengari is a complete Lua 5.3 virtual machine, parser, and base libraries ported from the Lua C library to JavaScript ES6, runnable in Node.js and the browser. It exposes the same C API as native Lua through a JS API, letting developers embed and execute Lua code in JavaScript environments.

## Use cases
- run Lua scripts in the browser
- embed a Lua interpreter in a Node.js application
- execute user-provided Lua code safely in a web app
- port Lua programs to JavaScript environments
- build a web-based Lua playground or REPL
- script game or app logic in Lua from JavaScript

## When to choose
- you need to run Lua code where only JavaScript is available (browser or Node)
- you want Lua 5.3 semantics without native compilation
- you're building tools that let users write Lua scripts in web apps

## When to avoid
- you need maximum Lua execution performance (use native Lua or LuaJIT)
- you need Lua 5.4 features or newer semantics
- you only need to parse or lint Lua rather than execute it

## Facets
- artifact type: library
- maturity: active
- function: interpreter, parser, programming-language
- domain: programming-languages, parsers, web-development, developer-tools
- platform: browser
- tags: lua-vm, es6, virtual-machine, lua-53, runtime, nodejs, javascript, web

## Member repositories
- fengari-lua/fengari (main) score 58

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:06:06.881871+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 2026-08-30T02:59:44.038248+00:00, confidence not recorded.
  - readme: https://github.com/fengari-lua/fengari (fetched 2026-08-28T04:06:06.881871+00:00, sha 2f2aab5d77cd)
  - registry_npm: https://registry.npmjs.org/fengari (fetched 2026-08-29T10:39:58.929050+00:00, sha 7f2d1d41df40)
- Data as of 2026-08-30T08:39:29.467469+00:00.