What does HackerNews think of js.js?

js.js: A JavaScript JavaScript interpreter

Language: JavaScript

More malicious extensions in Chrome Web Store | Jun 2023
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Those sidesteppings are outlawed by the Chrome Web Store policies.

There are JS-in-JS interpreters out there. They're just not allowed. https://github.com/jterrace/js.js/ https://github.com/marten-de-vries/evaljs
QuickJS JavaScript Engine | Jul 2019
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Definitely not the first JS VM compiled to the browser. Aside from JSC as another comment mentioned, there was also js.js which is SpiderMonkey compiled to JS (around 2012!),

https://github.com/jterrace/js.js/

This shouldn't be surprising - many VMs have been compiled to the Web, like Lua, Python (both CPython and PyPy!), etc., and JS is just another VM.
A pure JavaScript implementation of Git for Node and browsers | May 2018
There's a bunch: https://github.com/jterrace/js.js/
Microsoft Edge's JavaScript engine to go open-source | Dec 2015
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It's not as impossible as it sounds.

There are many JS engines which are extremely small compared to the big guys used in browsers. Most of them tend to grab a subset of the language and implement that.

For example, the creators of nginx created their own specialized engine called nginScript that runs JS for their stuff https://www.nginx.com/resources/wiki/nginScript/

There is even a javascript interpreter written in javascript which can be a good starting point to learn a bit how it works https://github.com/jterrace/js.js/
JavaScript runtime for Unreal Engine | Nov 2015
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No, because V8 has no interpreter (although they are working on one: https://code.google.com/p/v8/issues/detail?id=4280), only JIT, and JIT doesn't run inside asm.js.

asm.js-compiled JavaScript engine has been done already: https://github.com/jterrace/js.js.
Js2js: A revolutionary open-source compiler from JavaScript to JavaScript | Feb 2015
The footer says that if you want a real "Javascript to Javascript interpreter", to see js.js[0], which is a JS interpreter written JS; where the satirical js2js is a JS-to-JS compiler, something different. If you want a real JS to JS compiler, see Google's "Closure Compiler"[1].

[0]: https://github.com/jterrace/js.js/

[1]: https://developers.google.com/closure/compiler/ / https://github.com/google/closure-compiler

Show HN: Breach – A modular browser built on Chromium and Node.js | Jul 2014
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js.js¹? Also, take a peek at repl.it if you haven't already

[1] https://github.com/jterrace/js.js/

[2] http://repl.it/languages
What 4chan thinks of HN | May 2014
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This one is actually legitimate. Saw it on HN a while ago, really funny:

https://github.com/jterrace/js.js/
Game Programming Patterns – Bytecode | Mar 2014
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Security. When you want to run untrusted modding code.

It's hard to sandbox python or lua and block I/O and all system calls. 1 mistake and player computers are compromised.

Even with JS in browser you can't just eval(), you need sandboxing like https://code.google.com/p/google-caja/ or https://github.com/jterrace/js.js/ (200 times slower than js).
Vim.js - JavaScript port of Vim | Dec 2013
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There are already several PC emulators in JS, and there are at least two Javascript interpreters in JS:

This one is Spidermonkey compiled with Emscripten: https://github.com/jterrace/js.js/

And this one is a test-bed for new JS language features (or at least meant to be - don't know how far along it is): https://github.com/mozilla/narcissus
Java Virtual Machine in pure Node.js | Oct 2013
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https://github.com/jterrace/js.js/