One of the main talking points at Tech Ed was whether to use remoting or enterprise services to talk between service tiers. For the benefit of the guys at work I thought I'd try and collate some of the information thats available and draw some guidelines. I won't cover ASMX/WSE as I believe there is no argument there - for talking between services use ASMX.

Firstly, for an overview of the options for hosting objects and communicating with them, you can't beat Don Box's bullets:

• Services and Communications
• Services and Processes

Don however doesn't mention remoting as he is really against it. Rock Lhotka provides a view that includes remoting:

• Middle-tier Hosting: Remoting vs. Enterprise Services

These two articles from Richard Turner (a program manager working on "Indigo") give you the inside view.

• On the road to Indigo - Is .NET Remoting Dead?
• On the road to Indigo: Prescriptive Guidance for Today's Technologies

Finally, another good roundup is by Aaron Skonnard reviewing Richard Turner's Tech-Ed session:

• TechEd: SO Prescriptive Guidance (Richard Turner)

I think the general guidance from all these articles is that remoting is OK given the following rules:

1. Only use it between tiers on the same machine (Otherwise use DCOM/ES instead)
2. Don't use any of the custom stuff like formatters and sinks
3. Don't use it at the service boundary (Use ASMX instead)
4. You MUST use remoting to communicate between app domains in the same process
5. You may have to do some rework when Indigo arrives