hermes VS ChakraCore

Hermes is a big one as well: low startup latency, low memory

https://hermesengine.dev/

Hermes

InstagramBundle.js.hbc.spk.xz is likely a compressed version of Hermes bytecode (js.hbc)"

In React Native's case, it uses an engine called Hermes:

📜 I made JSON.parse() 2x faster: Radek proposes to improve the performance of Hermes by using very fast C++ libs based on SIMD instructions. Interesting to read even if you don't use React-Native. Ongoing discussions on the Hermes PR.

Thanks! There's a preliminary PR with a discussion here: https://github.com/facebook/hermes/pull/933 (and broader context here: https://github.com/facebook/hermes/issues/811 ). But we'll see if there's any interest on Hermes' side to merging it. They definitely want to improve the parser, but it's unclear to me if they want to take on the simdjson/simdutf dependencies.

For me it’s a JS engine for React Natve - https://hermesengine.dev/

💉 Building and injecting a JS bundle a basic concept: If the native code wasn’t changed, simply create JS bundle and inject it into the precompiled application. (You must take an extra step to convert a js file to bytecode if you use the Hermes js engine.)

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.