One might also look at Project Orleans Microsofts approach on actors.(which was released last week)
This is the projects website:
http://research.microsoft.com/en-us/projects/orleans/
Here is also a good talk from build 2014 as introduction
Using Orleans to Build Halo 4’s Distributed Cloud Services in Azure
http://channel9.msdn.com/Events/Build/2014/3-641
Please note that the bits for download as posted today are CTP.
Introduction to Orleans: http://felixnotes.com/orleans-microsofts-take-on-the-actor-pattern-in-net/
And yes, it was also open sourced: https://github.com/dotnet/orleans