XAML is used extensively in .NET Framework 3.0 & .NET Framework 4.0 technologies, particularly Windows Presentation Foundation (WPF), Silverlight, Windows Workflow Foundation (WF), Windows Runtime XAML Framework and Windows Store apps. In WPF, XAML forms a user interface markup language to define UI elements, data binding, events, and other features. In WF, workflows can be defined using XAML. XAML can also be used in Silverlight applications, Windows 10 Mobile (previously Windows Phone) and Universal Windows Platform apps, also called Windows Store apps.