Introduction -- Ambient Intelligence: A New Computing Paradigm and a Vision of a Next Wave in ICT -- Context and Context Awareness of Humans and AmI Systems: Characteristics and Differences and Technological Challenges and Limitations -- Context Recognition in AmI Environments: Sensor and MMES Technology, Recognition Approaches, and Pattern Recognition Methods -- Context Modelling, Representation, and Reasoning: An Ontological and Hybrid Approach -- Implicit and Natural HCI in AmI: Ambient and Multimodal User Interfaces, Intelligent Agents, Intelligent Behavior, and Mental and Physical Invisibility -- Towards AmI Systems Capable of Engaging in 'Intelligent Dialogue' and 'Mingling Socially with Humans' -- Affective Behavioral Features of AmI: Affective Context Aware, Emotion-Aware, Context-Aware Affective, and Emotionally Intelligent Systems -- The Cognitively Supporting Behavior of AmI Systems: Context Awareness, Explicit Natural (Touchless) Interaction, Affective Factors and Aesthetics, and Presence -- Concluding Remarks, Practical and Research Implications, and Reflections.