Whether it's tapping, flicking, pinching, or stretching, the vocabulary and gestures of user interfaces have changed a lot in the past year. Multitouch surfaces are now common across almost all platforms and device types. The new Windows Touch API, along with innovations from the Surface project, make it easier than ever to build rich, natural, multitouch interfaces for Windows applications. Natural User Interfaces in .NET is a hands-on guide to creating natural user interfaces (NUI) and great multi-touch experiences using the WPF and Silverlight multi-touch APIs. The book starts by introducing natural user interface (NUI) design concepts that everyone needs to know. It then quickly moves to the WPF Touch API and Surface Toolkit, guiding the reader through a multitouch NUI application from concept to completion. Along the way, readers will see where these concepts can be extended to Silverlight via its touch interface.