When Microsoft releases Windows Vista, the new operating system will support applications that employ graphics now used by computer games--clear, stunning, and active. The cornerstone for building these new user interfaces is XAML ("Zammel"), the XML-based markup language that works with Windows Presentation Foundation (WPF), Vista's new graphics subsystem.

An acronym for Extensible Application Markup Language, XAML offers a wealth of new controls and elements with exciting capabilities, including animation and rendering of 3D graphics. Windows developers are already jazzed by the...