1. General

1.1 What is WPF?

Windows Presentation Foundation (WPF) is the presentation subsystem feature of the .NET Framework 3.0. It is pre-installed in as a part of Windows Vista, It is also available for installation on Windows XP SP2 and Windows Server 2003. It supports the rich User Experiences (UX) that have been made possible by advances in hardware and technology since the GDI based UI architecture was initially designed in the 1980's.

Also refer to the separate section on XAML in this FAQ

1.2 What is XAML?

XAML is an extensible markup language base on XML. XAML can be thought of as a script for creating .NET 3.0 objects. It is particularly used in WPF as a user interface markup language to define UI elements, data binding, eventing and other features. It is also used in Windows Workflow Foundation (WF), in which the workflows themselves can be defined in XAML code.

1.3 What is XBAP?

XBAP stands for XAML Browser Application. XBAP allows for WPF applications to be used inside a browser. The .NET framework is required to be installed on the client system. Hosted applications run in a partial trust sandbox environment. They are not given full access to the computer's resources and not all of WPF functionality is available.