Cooperative Information Systems have emerged as a central concept in a variety of applications, projects, and systems in the new era of e-business. The conference at which the papers in this volume were presented was the ninth international conference on the topic of Cooperative Information Systems (CoopIS 2001), and was held in Trento, Italy on September 5-7, 2001. Like the previous conferences, CoopIS 2001 has been remarkably successful in bringing together representatives of many di?erent ?elds, spanning the entire range of e?ective web-based Cooperative Information Systems, and with interests ranging from industrial experience to original research concepts and results. The 29 papers collected here out of the 79 ones that were submitted, dem- strate well the range of results achieved in several areas such as agent te- nologies, models and architectures, web systems, information integration, m- dleware technologies, federated and multi-database systems. The papers th- selves, however, do not convey the lively excitement of the conference itself, and the continuing spirit of cooperation and communication across disciplines that has been the hallmark of these conferences.We would especially like to thank our keynote speakers: Philip A. Bernstein (Microsoft Research, USA), Edward E. Cobb (BEA Systems, USA), and Ma- izio Lenzerini (Universit'a di Roma "La Sapienza", Italy) for providing a portrait of the best contemporary work in the ?eld. We would also like to thank the many people who made CoopIS 2001 possible.

Cooperative Information Systems have emerged as a central concept in a variety of applications, projects, and systems in the new era of e-business. The conference at which the papers in this volume were presented was the ninth international conference on the topic of Cooperative Information Systems (CoopIS 2001), and was held in Trento, Italy on September 5-7, 2001. Like the previous conferences, CoopIS 2001 has been remarkably successful in bringing together representatives of many di?erent ?elds, spanning the entire range of e?ective web-based Cooperative Information Systems, and with interests ranging from industrial experience to original research concepts and results. The 29 papers collected here out of the 79 ones that were submitted, dem- strate well the range of results achieved in several areas such as agent te- nologies, models and architectures, web systems, information integration, m- dleware technologies, federated and multi-database systems. The papers th- selves, however, do not convey the lively excitement of the conference itself, and the continuing spirit of cooperation and communication across disciplines that has been the hallmark of these conferences.We would especially like to thank our keynote speakers: Philip A. Bernstein (Microsoft Research, USA), Edward E. Cobb (BEA Systems, USA), and Ma- izio Lenzerini (Universit'a di Roma "La Sapienza", Italy) for providing a portrait of the best contemporary work in the ?eld. We would also like to thank the many people who made CoopIS 2001 possible.