Basicly you can do webservices from REALbasic with the built in SOAP classes. But they are limited and I decided not to use them. So I got my own tool which not just enables SOAP in a REALbasic application, but also provides methods and classes so you can use the webservice as if you had it running as part of your application.
You can call the webservice methods. In the background our code creates XML code from your function call, sends that code to the server, receives an answer, parses the answer and returns the result to you. All transparently and you can see this source code and modify it if you like.
And if the WSDL changes, you just rerun our tool to get new code which you can add to your project.