Is it possible to have two virtual directories under the same website in IIS but have the virtual directories be using different versions of the .net framework?
For example, under the default website, can I have one virtual directory targeting the 2.0 framework and a second virtual directory targeting the 1.1 framework?
This is for IIS 6, thanks!
You are not saying which version of IIS you are using, but for 6.0 and up, just assign them to different application pools, and set the pools to use the right version of .Net.
You have to create an "application" for both of the virtual directories, and then you'd assign their ASP.NET version using the ASP.NET tab under web site properties.
Also, as @sunny mentioned, you'd need to have two different application pools, and each virtual directory would have to be pointed to a different application pool. Because different versions of ASP.NET cannot run within the same application pool.
It depends if you mark them as "applications". Application virtual directories can use different framework. Make sure you associate them to different application pools. Never mix two .NET framework versions in one application pool.
One important note: if you create a virtual directory as an application, you don't share session state and other application related objects. Also Server.MapPath("~") and other ServerURL related methods an properties will point to the physical directory of the virtual directory and not to the main root.
来源：https://stackoverflow.com/questions/284434/virtual-directories-with-different-net-frameworks