Progress in collaborative networks continues showing a growing number of manifestations including virtual organizations, virtual enterprises, dynamic supply chains, professional virtual communities, collaborative virtual laboratories, etc. with a wide spectrum of application domains. The realization that all these collaborative forms represent variations of a more general paradigm is leading to their consolidation into Collaborative Networks as a new scientific discipline. This book contains selected articles from PRO-VE'05, the sixth working conference on virtual enterprises, which was sponsored by the International Federation for Information Processing (IFIP) and held in Valencia, Spain. Being recognized as the most focused scientific / technical conference on Collaborative Networks, PRO-VE continues offering the opportunity for the presentation and discussion of both the latest research developments and practical application case studies. Following the IFIP vision, PRO-VE offers a forum for collaboration and knowledge exchange among experts from different regions of the world. The articles included in this book represent a comprehensive overview of recent advances in various domains and lines of development of collaborative networks. Of particular relevance are the topics of holistic approaches and breeding environments management, creation and management of virtual organizations and professional virtual communications, performance measurement and management, benefit analysis, trust management, process modeling and meta-modeling, ICT infrastructures and support services, legal issues, and case studies.