This article applies to ASP.NET 2.0. Background This article originated from a customer question on the ASP.NET site . What they are trying to achieve is running multiple sites under a single actual ASP.NET application. This can be useful to avoid the overhead of having a different appdomain per site. So the general idea is to have a single application, and to use sub-directories to represent the site. Let's call them 'pseudo-sites' as they are really just directories from the point of view of ASP.NET. For example, the app could have this structure: MyApp PseudoSites Site1 page.aspx uc.ascx Site2 Site2's files... Such pseudo-sites will necessarily have a number of limitations: e.g. they won't be able to each have their own bin, App_Code, and...