For  Visual  Studio  6.0  developers,  the  SOAP  Toolkit  is  available  for download at http://msdn.microsoft.com/downloads/default.asp?URL=/ code/sample.asp?url=/msdn-files/027/001/580/MsdnCompositeDoc.xml. The SOAP Toolkit 2.0 provides a more robust Web service creation expe- rience. It includes a client-side component that can be used to raise calls across   the   Internet,   contains   a   wizard   that   automatically   generates required .wsml and .wsdl files, and handles communication marshalling across the Internet. If you are developing with Visual Basic 6.0 and want to turn your DLLs into Web services, the SOAP Toolkit 2.0 is literally the only way to go. In  .NET,  SOAP  is  inherently  part  of  the  .NET  Framework,  so  creating and calling SOAP-based Web services is even easier than using the SOAP Toolkit and client-side components associated with Visual Studio 6.0. Once you install the framework, you have effectively established the foundation for SOAP Web services. The  .NET  Framework  is  free  to  download.  If  you  want  to  experiment with  Web  services  but  dont  know  where  to  start,  go  to  http://msdn .microsoft.com/downloads/default.asp?url=/downloads/sample.asp? url=/msdnfiles/027/000/976/msdncompositedoc.xml&frame=true and  download  the  .NET  Redistributable  Framework.  It  contains  all  the ingredients  that  are  needed  to  run  .NET  Framework  applications  and includes  the  CLR,  the  .NET  Framework  Class  Library,  and  ASP.NET. The download is only 21 MB, but pay attention to the hardware, soft- ware, and installation requirements. Later in this book we delve into build- ing .NET Web service consumers and providers, demonstrating how you build them, and documenting how they work. Several   non-Microsoft   development   environments   provide   built-in SOAP support. Because SOAP is now an industry standard, you can also expect ever more platforms and products to support it. The Pros and Cons of SOAP Prior to .NET, leveraging SOAP on the client required the client to have the SOAP client component installed on the clients PC to initialize the SOAP object  and  make  SOAP-based  Web  service  calls.  Although  the  SOAP Toolkit doesnt require much space on a users machine, Internet options sometimes need to be tweaked to support client-side calls. For the general user, this could spell problems. In addition to this, the SOAP-based Internet calls support a limited num- ber  of  data  types.  If  a  developer  is  expecting  unconventional  in,  out,  or 12 Chapter 1