I am using the Cassini.Server class directly in my windows form app like this... server = new Cassini.Server(8080,"/",@"C:\web1"); server.Start(); I can now connect to the url http://localhost:8080/ and receive a response (directory listing) from the Cassini.Server that is running nicely in my windows form app. Now, what I really want to do is expose a few webservices from my windows form app to get and set data that is needed in this windows form app. This means that the dll that contains the .asmx implementation needs to call into my windows form app's main AppDomain...right ??? Which means that the .asmx implementation needs to be able to get a handle to this AppDomain, and then use something like DoCallback() to call into the AppDomain...right ??? How do I get the AppDomain handle, or am I off in the weeds here. Any nice examples of this already out there ? -- THanks, Andrew