This book constitutes the joint refereed proceedings of six international workshops held as part of OTM 2003 in Catania, Sicily, Italy, in November 2003.

The 80 revised full workshop papers presented together with various abstracts and summaries were carefully reviewed and selected from a total of 170 submissions. In accordance with the workshops, the papers are organized in topical main sections on industrial issues, human computer interface for the semantic Web and Web applications, Java technologies for real-time and embedded systems, regulatory ontologies and the modeling of complaint regulations, metadata for security, and reliable and secure middleware.