virtual environment (n)~ A runtime container that defines the resources available to application processes launched from an application package. Resources include files directories registry keys and values fonts COM objects and services. These resources originate from the application package but may be changed by the application. Changes to resources made by the application are isolated from other applications launched from different packages or by different users. Changes made by the application take precedence over package-defined resources and persist from one launch of the application to the next. virtual environment (n)~ An environment composed of virtual machines.