XAML is a markup language used to define dynamic or static UIs for .NET applications. Though Windows Vista would be used to design XAML UIs, they can be applied to Windows XP or Windows 2003 too.

XAML is similar to MVC in terms of the separation of the UI code from application logic.

XAML is bound to Windows Presentation foundation to build a UI in .NET 3.0 and Windows Vista.

XAML Features:

- XAML inherits all XML definitions and rules.

- It also contains HTML, XHTML and other markup languages for UI.

- Every XAML element represents a .NET CLR class due to which working with XAML becomes simple.

- The application logic can be put in a separate file or be embedded in XAML file itself as XAML in conjunction with Windows Presentation Foundation model to provide the developers design a good UI in ASP.NET.

- XAML files get compiled to BAML files which are smaller than XAML and easier to read which make them faster to load.

Workflows serve the purpose of automating business processes. Now, since each type of business has a wide range of problems; therefore, a workflow platform needs to be extensible. WF provides you with a set of base activities, such as IfElse, Code, and Delay, to build a workflow. You can extend these activities or build new activities to meet your requirements. Besides activities, you can also extend services, such as tracking, management, and persistence, provided by the runtime engine.