Building applications for the Internet means using protocols and creating browser-based user interfaces, as you've done in the preceding two chapters, but also opens an opportunity for exchanging business documents electronically. The emerging standards for this type of activity center around the XML document format and include the SOAP transmission protocol, XML schemas for the validation of documents, and XSL for rendering documents as HTML.
In this chapter, I'll discuss the core XML technologies and the extensive support Delphi has offered for them since version 6. Because XML knowledge is far from widespread, I'll provide a little introduction about each technology, but you should refer to books specifically devoted to them to learn more. In Chapter 23, I'll focus specifically on web services and SOAP.