jterrace/js.js

Health v2 · maintenance only

Flags: no_releases no_license

Adoption not part of the score

1082 stars · 59 forks observed · 2026-08-28

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-30, confidence not recorded

js.js is a JavaScript interpreter written in JavaScript, created by compiling SpiderMonkey to LLVM and translating it with Emscripten. It exposes a JSAPI-style wrapper so scripts can evaluate and run JavaScript code inside a browser or Node.js environment.

Use cases

• run untrusted javascript in a sandboxed interpreter inside the browser
• evaluate javascript code from within a javascript application
• embed a separate javascript execution context in node
• build an in-browser javascript playground or REPL
• execute user-supplied scripts safely without eval

When to choose

• you need to run JavaScript code isolated from the host page's real JS environment
• you want a self-contained interpreter that works in browser and Node.js
• you're experimenting with interpreter-in-interpreter techniques or teaching

When to avoid

• you need fast execution - it's roughly 200x slower than native SpiderMonkey
• you need a small dependency - the compiled build is ~3MB (594KB gzipped)
• you need an actively maintained project - it dates from 2012 with no recent development
• you just want to evaluate trusted code - native eval or Function is far simpler

Facets

library · maturity abandoned

interpreter compiler developer-tools programming-languages compilers developer-tools web-development browser wasm javascript-interpreter spidermonkey emscripten transpilation sandboxing nodejs javascript

Member repositories

For agents

markdown · JSON · MCP: product_card(name="jterrace/js.js")