An invited collection of peer-reviewed papers surveying key areas of Roger Needham’s distinguished research career at Cambridge University and Microsoft Research. From operating systems to distributed computing, many of the world’s leading researchers provide insight into the latest concepts and theoretical insights–many of which are based upon Needham’s pioneering research work. A critical collection of edited-survey research papers spanning the entire range of Roger Needham’s distinguished scientific career, from operating systems to distributed computing and security. Many of the world’s leading researchers survey their topics’ latest developments and acknowledge the theoretical foundations of Needham’s work. Introduction to book written by Rick Rashid, Director of Microsoft Research Worldwide.