Aren't go routines pretty similar to WebWorkers, but with special syntax for creating them (and sending/receiving messages over channels) and perhaps lighter weight (though that may just be an implementation issue with current JS engines)?
Edit: nevermind, it looks like go routines can share memory, (but channels are the preferred method of synchronization): https://golang.org/ref/mem
Edit: nevermind, it looks like go routines can share memory, (but channels are the preferred method of synchronization): https://golang.org/ref/mem