Dart Isolate vs Akka
Isolates differ from Akka actors in many ways:
isolates do not share memory, that is, are isolated just like Unix processes are
as a result, when an isolate is spawned using spawn, all data in the current isolate are duplicated
isolate has no central method like receive - or, better say, that method is hidden under the hood. That method takes tasks from execution queue and executes them one by one. This is similar to as GUI thread works. Task are created with callback methods inside. Callbacks are used everywhere in Dart.
The description http://en.wikipedia.org/wiki/Akka_(toolkit) seems to be similar to what Dart isolates are.
Akka seems more advanced. There is no trancparency yet if you communicate to isolates on the same host or another host for example.