Cooperative Information Systems : 9th International Conference CoopIS 2001 Trento Italy September 5 7 2001 Proceedings This book constitutes the refereed proceedings of the 8th International Conference on Cooperative Information Systems CoopIS 2001 held in Trento Italy in September 2001. The 29 revised full papers presented together with three invited contributions were carefully reviewed and selected from 79 submissions. The papers are organized in topical sections on agent and systems; information integration; middleware platforms and architectures; models; multi and federated database systems; Web information systems; workflow management systems; and recommendation and information seeking systems