In this first volume of the book series Studies on the Semantic Web several non-monotonic extensions to description logics (DLs) are investigated, namely auto-epistemic DLs, circumscriptive DLs and terminological default rules, all of which extend standard DL inference mechanisms by forms of closed-world and default reasoning associated to common-sense features. A matchmaking framework is established for semantic resource descriptions formulated in the DL formalism that uses various DL inferences to judge resource compatibility. Special emphasis lies on mapping the technical formalities of model-theoretic semantics of DLs to more intuitive notions that abstract from the details of logic for the framework’s easier adoption in applications. The particular contributions of "Semantic Matchmaking with Nonmonotonic Description Logics" span the fields of non-monotonic reasoning with description logics in artificial intelligence, matchmaking of ontology-based descriptions and semantic web service discovery. A novel tableaux calculus for reasoning in circumscriptive DLs is introduced and it is demonstrated how the various nonmonotonic extensions to description logics can be used to realize common-sense features and local closed-world reasoning in a semantic web setting in general.