What Microsoft Office 2013 uses to сreate the user interface?
What [Office 2013][1] uses to create such nice user interface that work in Windows 7 and 8 ?  
What libraries, toolkits, frameworks ?  
It's really slick and clean, it uses Metro design patterns, massive amount of animations and asynchronousity in user interface.  
Look like it's not uses WPF.

  [1]: http://www.microsoft.com/office/preview
What Microsoft Office 2013 uses to сreate the user interface?
===

What [Office 2013][1] uses to create such nice user interface that work in Windows 7 and 8 ?  
What libraries, toolkits, frameworks ?  
It's really slick and clean, it uses Metro design patterns, massive amount of animations and asynchronousity in user interface.  
Look like it's not uses WPF.

  [1]: http://www.microsoft.com/office/preview