Will .NET Framework 3.0 run .NET Framework 2.0 apps?

This is a common question on the .NET Framework Setup Forum.

 Let me first answer this by YES!!! ABSOLUTELY!!! WE DESIGNED IT THAT WAY!!!!

 Ok now that is out of the way, I would like to explain why.  .NET Framework 3.0 is built on the .NET Framework 2.0 Libraries.

 The following link is from MSDN Learning and explains in much more detail how this works.


 Next I would like to reference the common Versioning Questions regarding the .NET Framework.  MSDN also does a greate job of this:


From the above reference this is one of my favorite quotes: 

Q: How does the .NET Framework 3.0 relate to the .NET Framework 2.0?

A: The .NET Framework 3.0 is an additive release to the .NET Framework 2.0. The .NET Framework 3.0 adds four new technologies to the .NET Framework 2.0: Windows Presentation Foundation (WPF), Windows Workflow Foundation (WF), Windows Communication Foundation (WCF), and Windows CardSpace. There are no changes to the version of the .NET Framework 2.0 components included in the .NET Framework 3.0. This means that the millions of developers who use .NET today can use the skills they already have to start building .NET Framework 3.0 applications. It also means that applications that run on the .NET Framework 2.0 today will continue to run on the .NET Framework 3.0.