This is probably a very basic question, but I cannot seem to find any 
Microsoft documentation regarding the answer.

Is there a new version of the CLR for .NET Framework 3.5?

If not, is the 2.0 CLR being modified by the .NET Framework 3.5 install to 
include "red bits" / "green bits" to the 2.0 CLR?

.... or were no changes to the CLR needed to add the features present in .NET 
Framework 3.5?

This is a fundamental question because we need a plan for regression testing 
of a million line .NET Framework 2.0 code base, and if I can avoid those 
regression tests because of "Zero" changes to the CLR, it would dramatically 
benefit my migration path and processes for .NET Framework 3.5 upgrade.

Thank you for any help or resources you can point me to to address this issue.

There has to be a nice .NET Framework / CLR version "one sheet" out there 
that explains the .NET Framework / CLR versions in more detail especially for 
..NET Framework 3.5

On Aug 13, 8:00 am, Dan Edgar 
wrote:

> This is probably a very basic question, but I cannot seem to find any
> Microsoft documentation regarding the answer.
>
> Is there a new version of the CLR for .NET Framework 3.5?


I agree ... I am confused as well.

Here's why? All I read out there ... is that there is a new version of
the CLR shipping with .NET Framework 3.5.

However, I've installed Orcas Beta 2 ... targeted the 3.5 version of
the framework ... built a sample WPF application that targets the 3.5
version of the framework ... and then printed out the
System.Environment.Version value ... and it shows: 2.0.50727.1378

Then, I modify that same project ... target the 3.0 version of the
framework ... remove the 3.5 references and using statements ... and
evaluate the System.Environment.Version value ... and it again shows
2.0.50727.1378!

What?!

That doesn't make sense. I would expect to see a 3.0.x version in the
first case and a 2.0.x version in the second case ...

http://www.danielmoth.com/Blog/2007/05/clr-v20-remains-at-same-version.html

Just found this ... it all makes sense now ... the answer is
simply ... that there isn't a new version of the CLR! And thus the
versions I am seeing ... but boy, I was confused based on what I've
been reading.

For example ... check out this wikipedia article (I know, I know
wikipedia isn't always right):
http://en.wikipedia.org/wiki/.NET_Framework#.NET_Framework_3.5

Thanks Mr. Moth for some clear posts on the matter!