This book presents scientific interactions between the three interwoven and challenging areas of research and development of future ICT-enabled applications: software, complex systems and intelligent systems. Software intensive systems heavily interact with other systems, sensors, actuators, and devices, as well as other software systems and users. More and more domains involve software intensive systems, e.g. automotive, telecommunication systems, embedded systems in general, industrial automation systems and business applications. Moreover, web services offer a new platform for enabling software intensive systems. Complex systems research focuses on understanding overall systems rather than their components. Such systems are characterized by the changing environments in which they act, and they evolve and adapt through internal and external dynamic interactions. The development of intelligent systems and agents features the use of ontologies, and their logical foundations provide a fruitful impulse for both software intensive systems and complex systems. Research in the field of intelligent systems, robotics, neuroscience, artificial intelligence, and cognitive sciences is a vital factor in the future development and innovation of software intensive and complex systems.