I have been testing Umbraco because it's the most popular open source CMS in .NET out there and I was curious. It surprised me that is not possible to run it in a virtual directory.
After working some time with ASP.NET and ASP.NET MVC I noticed that sometimes allowing your application to run in a virtual directory instead as well as in a subdomain can lead to bugs and other annoying problems that could be avoided by simply assuming that the application won't run under that conditions.
Is really that important adding support for virtual directory or nowadays subdomains are so easy to make that is not worth the effort?