Hi,
You can compile your application against any framework version. The
frameworks can co-exist side by side, so can VS.NET versions. It is only
that VS is locked down to one particular framework version.
You need not recompile your application and redistribute every time there is
a framework change, unless there is a breaking change in the newer version.
In most cases this might not be the case.
BTW, the app config file can contain elements that can govern which version
of .NET runtime is to be used by the application. Specifically the
supportedRuntime and the requiredRuntime elements.
The supportedRuntime can be used to indicate which version of rutime the app
supports and any app built with v1.1 should ideally specify the same.
The requiredRuntime should be used only if the application supports only
version 1.0 of the common language runtime.
For more info refer to MSDN doc:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/htm
l/cpcontargetingnetframeworkversion.asp
Also, have a look at the links at
http://msdn.microsoft.com/library/en-us/cpguide/html/cpconside-by-sideexecut
ion.asp?frame=true