The wealth of functionality of middleware solutions such as application servers and Web services increasingly overburdens developers and administrators. These functionalities have been developed and managed mostly with the help of administration tools and corresponding configuration files. Although this approach is flexible, it's problematic because the conceptual model underlying the configurations isn't explicit. An ontology-based approach facilitates the management and administration of application server- and Web services-based applications. The proposed design integrates the ontology infrastructure in existing application servers and has been prototypically implemented in KAON SERVER, an amalgamation of JBoss and the KAON ontology tool suite.