Currently, there are two well known languages that support actors: Erlang and Scala.
The core concept is that modules (actors) in your application communicate exchanging messages, which makes concurrency very easy to handle for developers.
This is in contrast to thread-based concurrency (like in C++), where the developer has much more work to do to get the system working correctly.
The following blog post discusses a possible implementation of the actor model in go.
Actor-like pattern in go