Mozilla is working on a spec for something called SharedArrayBuffer, which will allow Workers other than the main thread of execution to share memory. The reas

Mozilla is working on a spec for something called SharedArrayBuffer, which will allow Workers other than the main thread of execution to share memory. The reason for this is that as soon as you have separate threads sharing memory, it introduces non-determinsism into the mix. When developers use synchronization mechanisms incorrectly, or not at all, this can lead to deadlock between threads. This must not be allowed to occur on the main thread shared with the rendering engine. So keep your eyes out for SharedArrayBuffer. The event loop is very important to the existing language semantics and isn't going anywhere.