Collaborative networked organizations, either as a collaboration among organizations such as virtual enterprises / virtual organizations, or collaboration among people such as professional virtual organizations, or even a mixed combination such as in e-Science, represent a very dynamic research and development area. Collaborative networked organizations - for which a growing number of case studies can be found nowadays in different sectors of industry, services, and even governmental organizations - provide a basis for cooperation, competitiveness, world-excellence, and agility in turbulent market and environment conditions. In the case of companies, collaborative networks can support them to identify and exploit new business potential, boost innovation, and increase their knowledge. Processes and Foundations for Virtual Organizations contains selected articles from PRO-VE'03, the Fourth Working Conference on Virtual Enterprises, which was sponsored by the International Federation for Information Processing (IFIP) and held in Lugano, Switzerland in October 2003. This fourth edition includes a rich set of papers revealing the progress and achievements in the main current focus areas: -VO breeding environments; -Formation of collaborative networked organizations; -Ontologies and knowledge management; -Process models and interoperability; -Infrastructures; -Multi-agent approaches. In spite of many valid contributions in these areas, many research challenges remain. This is clearly stated in a number of papers suggesting a new research agenda and strategic research roadmaps for advanced virtual organizations. With the selected papers included in this book, PRO-VE pursues its double mission as a forum for presentation and discussion of achievements as well as a place to discuss and suggest new directions and research strategies.