Yolanda Gil has announced a useful analysis of the differences and similarities of W3C XML Schema, RDF Schema and DAML in the context of the requirements of knowledge representation.

For each issue (such as contexts, inheritance, object classes) the table explains how each of the languages implement (or do not implement) the feature, and links to examples.

In a follow-up message to Gil's announcement, Oscar Corcho also provided links to several papers he and Asunción Gómez-Pérez have written on ontology specification languages.