MORAI presents an innovative digital twin simulation platform designed to expedite the development and evaluation of autonomous vehicles, urban air mobility solutions, and maritime autonomous surface vessels. This platform utilizes high-definition mapping and an advanced physics engine to seamlessly connect real-world applications with simulated testing environments, ensuring all critical components for validating autonomous systems are included, such as those for self-driving cars, drones, and unmanned marine vehicles. It features a comprehensive array of sensor models, which encompass cameras, LiDAR, GPS, radar, and Inertial Measurement Units (IMUs). Users have the capability to create intricate and varied testing scenarios derived from actual data, including those based on logs and edge cases. Furthermore, MORAI's cloud-based simulation framework enables safe, efficient, and scalable testing processes, allowing multiple simulations to operate simultaneously while assessing various scenarios in parallel. This robust infrastructure not only enhances the reliability of testing but also significantly reduces the time and costs associated with the development of autonomous technologies.