A configuration system is organized with a configuration file for each node in an application hierarchy. Each configuration file includes one or more directives for applying a configuration setting to a node. Each configuration setting is associated with one or more objects that define properties of the configuration setting. The properties define rules for the configuration setting such as inheritance, persistence, validation, merging, and the like. Defining rules for each configuration setting in an object allows the configuration settings to be declaratively extended and edited without requiring user to have knowledge of the underlying hierarchy.