status.modern.ie lists it as "Under Consideration" still for all browsers:
http://dev.modern.ie/platform/status/moduleses6/?filter=f3e0...SystemJS is a polyfill (and extender post-polyfill) that is great with support for plugins, transpiling ES6, and format detection for CommonJS, AMD, and even "Global" modules: https://github.com/systemjs/systemjs
Also recommended, is JSPM (http://jspm.io) which is a package manager that utilizes the features of SystemJS and configures SystemJS to load NPM packages (akin to Browserify/Webpack) and Github repositories (somewhat similar to Bower).
