How best to communicate between AppDomains?

Question

I have an application that needs to send a moderately high volume of messages between a number of AppDomains. I know that I could implement this using remoting, but I have

Answer 1

I want to expand on xOn's answer. He recommends using either WCF or MarshalByRefObject, but given that the question asks about communication between AppDomains, and not about communication between processes, I think the MBRO approach is significantly simpler to implement, and is therefore the right answer.

When I was researching this issue myself, I struggled at first to understand how the child AppDomain could communicate with the parent, until I realized that you could pass a handle to a MBRO object into the child, and the child could then unwrap that handle to communicate back to the parent (or any other AppDomain). I posted a solution to my own question here.

I subsequently learned that you can define an interface, implement that interface on a complex class, and then pass a handle to only the interface. This can greatly reduce the number of assemblies that might be required to load the child AppDomain.