Hermes

It’s a collection of superfast tests or detects as we like to call them which run as your web page loads, then you can use the results to tailor the experience to the user. It tells you what HTML, CSS and JavaScript features the user’s browser has to offer.

Babel will turn your ES6+ code into ES5 friendly code, so you can start using it right now without waiting for browser support.

It is a linter, compiler, bundler, and more for JavaScript, TypeScript, JSON, HTML, Markdown, and CSS. It is designed to replace Babel, ESLint, webpack, Prettier, Jest, and others. It unifies functionality that has previously been separate tools. Building upon a shared base allows us to provide a cohesive experience for processing code, displaying errors, parallelizing work, caching, and configuration.

It is a safer way to build robust front-end web applications. With it, typos and type-errors are immediately caught and shown to you in your editor, without even needing to compile your code. Refactor any field or method with ease, with the confidence that if you mess it up the editor will tell you immediately

It is an experimental JavaScript toolchain. It includes a compiler, linter, formatter, bundler, testing framework and more. It aims to be a comprehensive tool for anything related to the processing of JavaScript source code.

Sucrase is an alternative to Babel that allows super-fast development builds. Instead of compiling a large range of JS features down to ES5, Sucrase assumes that you're targeting a modern JS runtime (e.g. Node.js 8 or latest Chrome) and focuses on compiling non-standard language extensions: JSX, TypeScript, and Flow.

This allows applications and libraries originally designed to run as standard executables to be integrated into client side web applications.

It is a compiler powered by Babel designed to make F# a first-class citizen of the JavaScript ecosystem.

It supports the ES2019 specification including modules, asynchronous generators and proxies. It optionally supports mathematical extensions such as big integers (BigInt), big floating point numbers (BigFloat) and operator overloading.