Shared memory? Is that also maybe going to be implemented on chrome? I would not have expected shared with code running on the web/in a browser. I'm confused about the goals of ECMA and how ECMA relates to JavaScript.
That's memory shared between the main thread and Web Worker threads. While it's exciting from an "easily implementing multi-threaded applications" point of view, given the nature of the objects, it doesn't actually allow sharing any data that couldn't be shared without the new spec.