Hermes JavaScript engine for React Native on Android.

open source, new javascript engine for React Native from Facebook
to get (much) better runtime performance it is using "Ahead Of Time" instead of "Just In Time"
compiling to byte code representation, an approach typical for "native" mobile apps anyway.

facebook/hermes: Hermes is a small and lightweight JavaScript engine optimized for running React Native on Android. @GitHub

React Native on Twitter: "Today Facebook is open sourcing Hermes, a small and lightweight JavaScript engine optimized for running React Native on Android. We are currently publishing a new patch release for React Native which will contain Hermes as opt-in. https://t.co/YUFCqvTrAV"

Enabling Hermes · React Native

https://hermesengine.dev/

Chain React 2019: Hermes Engine Announcement - YouTube

the key advantage is speed, achieved by doing `Ahead Of Time` compiling to bytecode
instead of typical (for JavaScript) `Just In Time`. This way the size is smaller (faster load) and avoiding a step of compiling before running. Smart. This is typical for other mobile platforms, so it makes sense.

While the presenter claims that Node.js (server side) and browsers are not objectives,
this approach could be used for server side apps and it could be beneficial in particular for ‘serverless’ (cloud functions, i.e. AWS Lambda) deployments, as well as for embedded IoT.
Since V8 JS engine is open source, it could be "forked" to do similar.