Hi there (ex Akka core team here). Yeah there's slight differences what the main concept is in those libraries. It kind of boils down to Akka's concept of an actor being more low level, and then adding the capabilities that Orleans offers as "the way" in means of extensions.

A virtual actor is very similar to an entity in Akka that is running in cluster sharding and uses Akka persistence. It's just that it's not packaged up into the virtual actor concept by default. I would love Akka to provide a more hand-holding more Orleans style module to be honest, it's a great concept and way to think about systems :-)