We will start by examining ActiveX Data Objects (ADO) 2.5 and its ability to work with XML data. ADO 2.5 simplifies programmatic access to data. In the second half of this tutorial, we'll discuss two Internet Server Application Programming Interface (ISAPI) extensions for Microsoft Internet Information Server (IIS). The first ISAPI extension allows you to retrieve data directly from a SQL Server 6.5 or 7.0 database in XML format using a Web browser.
The second extension enables IIS to pass the XML directly to the client computer. It can also automatically transform XML documents to other formats using an XSL document on the server if the client does not have Internet Explorer 5 installed. Although the second ISAPI extension won't be used to build data services components that can access data, it's included in this tutorial so that it can be discussed along with the first ISAPI extension. Let's begin by looking at the XML features found in ADO 2.5.