Open-source alternatives to ES Transpiler

ECMAScript 6 compatibility shims for legacy JS engines

SystemJS is a dynamic dependency manager and universal module loader that resolves and executes JavaScript modules across different browser and server environments. It functions as an import map polyfill, mapping bare module specifiers to absolute URLs to manage dependencies without requiring a build step. The project provides a system for integrating diverse formats, including AMD and global scripts, into a modern ES module workflow. It enables browser module polyfilling for environments that lack native support for ES modules and import maps, and it allows for dynamic runtime hot-reloading