Breakthrough programming .NET era [closed]

Question

I wonder what are .NET technologies / C# language improvements you consider as breakthroughs in the .NET era for the last 5-10 years. I mean technologies that shifted developers' minds.

For example DirectX made assembler nearly abandoned for game programming in the end of the 20th century and jQuery extremely simplified Ajax web development as well as JavaScript code reusability.

What kind of breakthrough .NET technologies do you expect in the future and what modern .NET technologies are just a light evolution of well known approaches?

Do you consider .NET 4.0 parallel extensions and other improvements as breakthrough, or maybe we have reached the point when nothing radical is expected in modern programming?

Answer 1

WPF, with its break from the traditional Windows UI scheme (bye bye Window Handles) and rich data binding, is definitely the biggest game-changer I've encountered. It's even more of a change than when I moved from writing simple C++ interfaces via MFC to working with C# and WinForms. This technology is completely changing the way that I think about user interface development.