>So, does that mean that .NET applications will be able to expose interfaces by means of "self-describing components"? Without distributing source code? I assume it does this without the extra overhead associated with COM. Would VFP be able to access these interfaces through the COM interop layer, in the same way it can get to the .NET Framework?
Yes. .Net provides component based access just like COM does but without the associated DLL hell. You simply copy files (DLLS) either into the app directory or somewhere on its path or in the DLLCache directory and those classes exposed become available.
>My concerns about performance and overhead come from the understanding that Web Services always communicate over http by means of XML messaging. Is that correct? I think that would mean that each server hosting a Web Service would require IIS or some other web server, and there would be additional overhead creating/consuming the XML. To be honest, I have no idea how this compares to the overhead associated with DCOM. Like you said, other factors may outweigh performance in this area.
DCOM is a binary format optimized for wire transfer. SOAP/Web Services is optimized for full featured access and running over a relatively slow network in a disconnected environment. DCOM will still be needed for 'connected' components, since .Net doesn't provide this at this point. Frankly I haven't dug deep enough to know exactly how some of the stateless remoting features work, but if there are any you can bet they'll use DCOM at a lower level that hides the complexity from the app.
Performance is definitely an issue with Web Services, but it depends on how applications are written really. I've never found DOCM over a network connection terribly fast anyway, so the difference between a Web Service and DCOM may not always be significant enough.
Running IIS is not really a problem the way I see it. You'll have to run NT/2000 anyway and having a Web server running is not going to be a huge issue. However, .Net also provides lower level HTTP Service features you can plug into a standalone application without running IIS. IOW, a HTTP server in an object as well as a TCP/IP based remoting feature that's possibly more efficient than the Web service architecture, but requries more work for the interaction.
>>+++ Rick ---
>Balance?
That's it!
>BTW, looking forward to your sessions at DevCon. Thanks.
Me too <s>...
