engine262 VS ChakraCore

engine262

Indeed. ECMA-262 has been implemented using JavaScript https://github.com/engine262/engine262.

Node.js is not the only JavaScript runtime. JavaScript runtimes have been written using JavaScript alone, see engine262. There is also Deno, QuickJS, txiki.js, Bun, none of which use COmmonJS by default, SpiderMonkey, et al.

for an interpreted language like JS, this project is really nice https://github.com/engine262/engine262. More or less 2 parts: parser and evaluator

That is a bit complex, so here's a list of JS engines: if you pick one written *in* JS, that would probably be most useful -- engine262 for example

then you might be impressed by https://github.com/engine262/engine262 as well

Engine 262

It's outside of what you asked for, but here's a JavaScript engine in JavaScript. Might make for some interesting bedtime reading!

Interesting to see a JS implementation written in JS:

https://github.com/engine262/engine262/

(The readme explains what the point of it is.)

I thought it would be a fun weird project to make Servo work with MS' abandoned JavaScript engine:

https://github.com/chakra-core/ChakraCore

Of course it is written in C++ and you'd probably want a pure Rust browser. But it is sad seeing that fairly complete open source JIT JavaScript engine sit and rot.

The JS engine is open source: https://github.com/chakra-core/ChakraCore

ChakraCore

Not to forget the engine Charka: https://github.com/chakra-core/ChakraCore

The only bit of the old Edge that had its source emancipated. It was/is? quite performant.

As a Linux user, I very much think Microsoft should have continued Trident and Chakra. Apple also should have continued releasing Safari for Windows. Our web QA setup was entirely built around Macs back then, but it was great to be able to test sites with Safari on Windows, and to have another responsive browser on Win32.

Edge was initially using Chakra but has been rebuilt using Chromium and the V8 engine.

https://github.com/chakra-core/ChakraCore/wiki/Architecture-...

I've found the source code to be quite readable too - albeit from a bug-finding perspective, not a strictly pedagogical one.

Furthermore, the new architecture decouples the JavaScript interface from the engine, enabling the use of other JavaScript engines such as Hermes, V8, or Chakra.

ChakraCore

I am astonished at the omission of ChakraCore, open sourced by Microsoft but sadly abandoned by them after they switched Edge to Chromium: https://github.com/chakra-core/ChakraCore. But it looks like it’s still chugging along as a community effort rather than being completely abandoned.