Here is a very simple calculator implemented as a WPF (Windows Presentation Foundation) XBAP (XAML Browser Application),
hosted within an IFrame. An XBAP can either be hosted by a browser or by a desktop Navigation Window.
The XBAP supplies its own navigation, as evidenced by the back and forward buttons within
the IFrame.
I plan on adding an article on WPF and XBAP to our articles section in the near future.