This text focuses on building intelligent successful systems. The book adopts a human-centred approach and considers various pragmatic issues and problems in areas like intelligent systems, software engineering, multimedia databases, electronic commerce, data mining, enterprise modelling and human-computer interaction for developing a human-centred virtual machine. The authors describe an ontology of the human-centered virtual machine which includes four components: activity-centered analysis component, problem solving adapter component, transformation agent component, and multimedia based interpretation component. These four components capture the external and internal planes of the system development spectrum. They integrate the physical, social and organizational reality on the external plane with stakeholder goals, tasks and incentives, and organization culture on the internal plane. The human-centred virtual machine and its four components are used for developing intelligent multimedia multi-agent systems in areas like medical decision support and health informatics, medical image retrieval, e-commerce, face detection and annotation, Internet games and sales recruitment. The applications in these areas help to expound various aspects of the human-centred virtual machine including human-centred domain modelling, distributed intelligence and communication, perceptual and cognitive task modelling, component based software development, and multimedia based data modelling. Further, the applications described in the book employ various intelligent technologies like neural networks, fuzzy logic and knowledge based systems, software engineering artifacts like agents and objects, Internet technologies like XML and multimedia artifacts like image, audio, video and text.