What is ASP.NET 4.0?
With ASP.NET 4.0 Microsoft introduces the next generation of web application technology.
ASP.NET simplifies development of powerful web applications.
It saves about 80% of code lines that the developer should write himself.
Additionally the tooling of ASP.NET has been extended considerably, which accelerates development with more functionality.
What about .Net 2.0?
Your .NET 2.0 applications are still operational on both .NET 3.5 and .NET4.
The .Net 3.5 framework is an expansion of the .Net 2.0 framework, with especially new graphic features. As the basic functions are unmodified, all applications written for.Net 2.0 also run with the new framework. Existing customers with version 2.0 have already been upgraded to 3.5.
New customers will automatically receive version 4.0.