> Fibres, goroutines, promises, futures, job queues, etc, are poor substitutes for Actors. They are not necessarily substitutes, they are lower level primitive

> Fibres, goroutines, promises, futures, job queues, etc, are poor substitutes for Actors. They are not necessarily substitutes, they are lower level primitives that allow more complex models, like Actors, to be implemented. All execution models have trade offs; and sometimes we might prefer an execution model without deadlock, livelock and starvation. So for a general purpose language, a complex model like Actors is ideally a library and not enforced as the only way of achieving concurrency.