A set of plug-in class loaders is provided in the class loader hierarchy. A plug-in class loader is provided for each class loader in the plug-in application's class loader hierarchy. Each plug-in class loader is associated with a single application class loader and is configured such that it delegates to its associated application class loader. All plug-in class loaders are also configured with a class path such that they may load plug-in classes from a directory that is specified within a configuration file. The loading of all plug-in classes is initiated by the application using the plug-in class loaders.