What happens in a .Net application when referencing .net 2 assemblies?

Question

I have an application that I want to upgrade to .NET 4, but I have a couple of third-party assemblies that reference the .NET 2 BCL.

I seem to remember reading something that says they should play well, but I cannot find documentation on this. (I think my question posed to Google is too broad, but not enough .Net 4 material)

Can someone help me find documentation on what will happen in this case?

Answer 1

If I read Scott Guthrie's post, Multiple Targeting Support (VS 2010 and .NET 4 Series) correctly, then this will work well.

Interesting: .NET 4.0 link to project 2.0 assembly

Answer 2

The .NET Framework 4 works side by side with older versions of the Framework. Applications based on earlier versions of the Framework will continue to run in the default version.

http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=0a391abd-25c1-4fc0-919f-b21f31ab88b7

Answer 3

I would like to reference StructureMap in one of my class libraries. Orginally it was created by VS2010 to use the .NET 4 client profile. It turns out that I had to change this to the full .NET 4 platform, otherwise the structural map would not be recognized.