The area of collaborative networks is being consolidated as a new discipline that encompasses and gives more structured support to a large diversity of collaboration forms in terms of applications, besides the 'traditional' sectors represented by the advanced supply chains, virtual enterprises, virtual organizations, virtual teams, and their breeding environments, new forms of collaborative structures are emerging in all sectors of the society. Collaborative networks are thus becoming a pervasive paradigm, giving basis to new socio-organizational structures.<BR>This book contains a number of selected articles from PRO-VE 2008; the ninth Working Conference on Virtual Enterprises held in Poznan, Poland, which was sponsored by the International Federation for Information Processing (IFIP) and the Society of Collaborative Networks (SOCOLNET). PRO-VE is well known as the most focused scientific and technical conference on Collaborative Networks, offering a major opportunity for the presentation and discussion of the latest research developments and industrial practice case studies. In line with the vision of IFIP and SOCOLNET societies, the PRO-VE Conference offers a forum for collaboration and knowledge exchange among experts from different regions of the world.<BR>The articles included in this book represent a comprehensive overview of recent advances in various domains and lines of research and development on collaborative networks. There is a special emphasis on the topics related to performance and value systems, VO breeding environments, VO creation and management, negotiations, collaborator platforms, collaborative problem solving, complex systems, business benefits, affective computing, and cultural issues. A large number of case studies and applications in industry and services are included.