This volume represents the seventh edition of the ECOOP Workshop Reader, a compendiumofworkshopreportsfromthe17thEuropeanConferenceonObject- Oriented Programming (ECOOP 2003), held in Darmstadt, Germany, during July 21–25, 2003. The workshops were held during the ?rst two days of the conference. They cover a wide range of interesting and innovative topics in object-oriented te- nology and o?ered the participants an opportunity for interaction and lively discussion. Twenty-one workshops were selected from a total of 24 submissions based on their scienti?c merit, the actuality of the topic, and their potential for a lively interaction. Unfortunately, one workshop had to be cancelled. Special thanks are due to the workshop organizers who recorded and s- marized the discussions. We would also like to thank all the participants for their presentations and lively contributions to the discussion: they made this volume possible. Last, but not least, we wish to express our appreciation to the members of the organizing committee who put in countless hours setting up and coordinating the workshops. We hope that this snapshot of current object-oriented technology will prove stimulating to you. October 2003 Frank Buschmann Alejandro Buchmann Mariano Cilia Organization ECOOP 2003 was organized by the Software Technology Group, Department of Computer Science, Darmstadt University of Technology under the auspices of AITO (Association Internationale pour les Technologies Objets) in cooperation with ACM SIGPLAN. The proceedings of the main conference were published as LNCS 2743.