IMO, this is *the* biggest feature of ES6, as it now means JS + DOM APIs are being spec'ed out that use them: Intent to ship for both FF & Chrome! https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/0Fs5P6Xgg9g https://groups.google.com/forum/#!topic/mozilla.dev.platform/Usb5PmsxM10