This book highlights current research into virtual tutoring software and presents a case study of the design and application of a social tutor for children with autism. Best practice guidelines for developing software-based educational interventions are discussed, with a major emphasis on facilitating the generalisation of skills to contexts outside of the software itself, and on maintaining these skills over time.  Further, the book presents the software solution Thinking Head Whiteboard, which provides a framework for families and educators to create unique educational activities utilising virtual character technology and customised to match learners' needs and interests. In turn, the book describes the development and evaluation of a social tutor incorporating multiple life-like virtual humans, leading to an exploration of the lessons learned and recommendations for the future development of related technologies.