James Turner at O'Reilly Radar – The Best and the Worst Tech of the Decade:

"SOAP was a particularly egregious failure, because it was sold so heavily as the final solution to the interoperatibility problem. The catch, of course, was that no two vendors implemented the stack quite the same way, with the result that getting a .NET SOAP client to talk to a Java server could be a nightmare. […] And the WSDL files that define SOAP endpoints are unreadable and impossible to generate by hand."