Sam says:


If you ever are in a position where you can control both ends of the wire...

There are much better protocols than SOAP

• Compactness
  
• Fidelity
  

I disagree. While compactness is a nice thing to have, I can't think of system I could build (outside of network gaming engines) that requires anything SOAP doesn't offer. Plus, if the gods on high who run XML can ever deliver unto us a binary XML, then you could imagine no re-engineering to take advantage of the newly compact form. As for fidelity: I'm against fidelity.

I believe that systems, regardless of how much of it you own, will be more robust using SOAP as opposed to other protocols. The key is two things: 1) versioning via namespaces, and 2) SOAP headers. Both of these allow us to build composable systems that can evolve. I also believe that OOP will be supplanted as the dominant programming model over the next 5-10 years as the XML and Web services model takes hold. I'm already building apps where I send hand-crafted SOAP messages within the application from one piece of code to another. Remember: the OS itself works off a message pump.