DirectX 9.0 is the latest evolution of the Microsoft 3D graphics technology for Windows. Direct3D, a major component of the DirectX Graphics subsystem, has evolved so rapidly in the last few years that the underlying programming paradigm has changed quite a bit from its origin. This article introduces the fundamental concepts of the unmanaged Direct3D architecture and illustrates how the managed Direct3D layer abstracts the unmanaged layer. Also, the author describes the Geometry, Texture, Device, and other classes and uses code from the Samples SDK. Yahya H. Mirza and Henry da Costa

Although most developers and APIs use the RGB scheme when working with colors, it's not the only available way to represent or select colors. For instance, the standard Windows color-selection dialog box allows you to work with the HSL color scheme in an indirect way. In this article, the author describes several color selection schemes, and uses GDI+ (via the System.Drawing namespace) to create a component that makes it possible for your own applications to provide a simpler, friendlier color chooser. Along the way, you'll get tips to help you use GDI+ in your own apps. Ken Getz

Scalable Vector Graphics (SVG), a W3C graphics standard built around XML, is one of several vector graphics technologies that allows fast, lightweight drawings such as charts and graphs to be rendered on the fly in an appropriate viewer. There are many advantages to such vector graphics, including conservation of bandwidth and storage media, and flexibility. This article explains these benefits and shows you how to easily add powerful, dynamic, interactive visual elements to your Web applications. Dennis Forbes

WebMethods make the development of XML Web Services easier by encapsulating a good deal of functionality, but there is still a lot of underlying XML processing that you have to be responsible for. For example, WebMethods do not validate messages against the implied schema. Because they are not validated, the response that's returned can result in unintended consequences. To address this, the authors extend the WebMethod framework by adding XML Schema validation through a custom SoapExtension class. Aaron Skonnard and Dan Sullivan

XPath is emerging as a universal query language. With XPath, you can identify and process a group of related nodes in XML-based data sources. XPath provides an infrastructure that is integral to XML support in the .NET Framework. The XPath navigation model is even used under the hood of the XSLT processor. In this article, the author reviews the implementation details of the XPath navigator and the XSLT processor and includes practical examples such as asynchronous transformations, sorted node-sets, and ASP.NET server-side transformations. Dino Esposito