This chapter is a walkthrough of the Web service development process. The process begins with message design where you create XML Schemas describing the service's input and output messages. Then you use xsd.exe to generate complex types from those schemas as needed. To implement the service itself, you use .NET attributes to shape each operation's messages according to the schema you defined earlier. To implement Web services infrastructure, you use a combination of reusable components and SOAP extensions that can be easily applied to any Web service. Finally, if your Web service is for public use, you can register it with UDDI enabling clients to implement UDDI scenarios such as the invocation pattern.