Metaverse Platform Implementation: AI, Security, and Applications provides a comprehensive exploration of the engineering and scientific principles behind the metaverse, a 3D digital world designed to replicate and enhance physical reality through some advanced technologies like Extended Reality (xR), Artificial Intelligence (AI), blockchain, 5G/6G, and computer vision. The book delves into the hardware (sensors, headsets, edge/cloud servers) and software (3D scene reconstruction, synchronization, AI processing) components that form the backbone of metaverse platforms, addressing critical aspects such as security, privacy, and social implications. It is organized into three parts and covers some foundational technologies such as neural rendering and semantic communications, security challenges (involving attack models and countermeasures), and real-world applications in healthcare (such as mixed reality-based stroke rehabilitation and telehealth innovations). By linking virtual and augmented reality to the broader metaverse ecosystem, this book serves as a crucial resource for engineers, scientists, and researchers in academia or industries working in the fields of robotics, smart cities, and intelligent transportation, offering valuable insights into the development of secure, efficient, and immersive digital 3D Internet environments.