Microsoft is showing off one more facet of its once-hidden intellectual property. On Tuesday, it placed the preliminary technical specifications for XAML—the Extensible Application Markup Language—under its Open Specification Promise, or OSP.The technical documentation will enable third parties to implement XAML formats in their client, server and tool products. It includes both the 2006 implementation of Microsoft’s XAML object mapping specification and the vocabulary specification for Windows Presentation Foundation (WPF). A spokesperson said that the final XAML documentation would be published by June 30.XAML is a declarative XML-based language used to define data binding, events and UI elements in WPF and Silverlight applications, and to define workflows in Windows Workflow Foundation.