Ahah. In my days SOAP libraries were kinda shitty up to the point I had to write my own to handle "non-standard" (actually very standard) WSDL definitions. SOAP consumption in one lang was okeish, especially Java or .NET. But interop — oh boy. The biggest issue were services exposing SOAP interface based on code-first approach, when you write some declarative code with annotations and library transforms it into WSDL and proxy endpoints.