This text discusses real information systems in which technologies have an essential role to play. It develops this perspective using the established discipline of semiotics, the theory of signs. A sign is anything that stands for something else within a certain community. This fundamental notion supports a unified treatment of human and technical aspects of information systems. The book covers such issues as: fundamental concepts such as "information", "data", "message", "communication", "knowledge", "organization", "system" and so forth. It comprises the proceedings of the Working Conference on Organizational Semiotics: Evolving a Science of Information Systems, which was sponsored by the International Federation for Information Processing (IFIP) and held in Montreal, Quebec, Canada in July 2001.