I think it is possible, but believe using different VMs to test and switch are better/easier (as long as you don't have a need to time bare metal response times)

>Do you know if it is possible to run two application in the same site where the application that runs in main/parent folder is compiled in .NET 2.0 or in sub-folder in .NET 4.0?
>
>For example:
>MainSiteName - ASP.NET 2.0
>MainSiteName\SubApp - ASP.NET 4.0
>
>So the user can start the 2.0 application as MainSite\Main20Page.aspx and can start 2.0 application as MainSite\SubApp\Main40Page.aspx?