How are the multiple Actors implementation in Scala different?

Question

With the release of Scala 2.9.0, the Typesafe Stack was also announced, which combines the Scala language with the Akka framework. Now, though Scala has actors in its stand

Answer 1

• scala.actors was the first serious attempt to implement Erlang-style concurrency in Scala that has inspired other library designers for making a better (in some cases) and more performant implementations. The biggest problem (at least for me), is that unlike Erlang processes, complemented with OTP (that allows for building fault-tolerant systems), scala.actors only offer a good foundation, a set of stable primitives that must be used for building a more high-level frameworks - at the end of the day, you’ll have to write your own supervisors, catalogs of actors, finite state machines, etc. on top of actors.

• And here Akka comes to the rescue, offering a full-featured stack for actor-based development: more idiomatic actors, set of high-level abstractions for coordination (load balancers, actor pools, etc.) and building fault-tolerant systems (supervisors, ported from OTP, etc.), easily configurable schedulers (dispatchers), and so on. Sorry, if I sound rude, but I think, there will be no merge in 2.9.0+ - I’d rather expect Akka actors to gradually replace stdlib implementation.

• Scalaz. Normally I have this library in the list of dependencies of all my projects, and when, for some reason, I can’t use Akka, non-blocking Scalaz Promises (with all the goodness, like sequence) combined with the standard actors are saving the day. I never used Scalaz actors as a replacement for scala.actors or Akka, however.