Here. "The following document describes changes between versions of the .NET Framework that might affect the backward or forward compatibility of your application. Information is also provided about the types of changes that can cause incompatibilities, ways to modify your application to work around incompatibilities, and how to test and run your application on different versions of the .NET Framework."
And so begins the grand experiment of whether it's actually possible to version the .NET runtime and keep everything running and working.
