Many industries are transitioning to I4.0 production models by adopting robots in their processes. In parallel, XR technologies have reached sufficient maturity to also enter the domain of industrial applications, with early success cases often related to the training of workers, remote assistance, access to contextual information and interaction with digital twins. This project looks at the intersection of both technologies: robots and XR. The use of robots in industry will be increasingly enhanced with XR applications, and workers must be able to understand both technologies and use hybrid solutions confidently. Achieving this is a challenge that education and training programs must meet. The objective of MASTER is to boost the XR ecosystem for teaching and training of robotics in manufacturing by providing an Open XR platform that integrates key functionalities for creating safe robotic environments, programming flexible robotic applications (programming by demonstration in flexible robotic application development) and integrating advanced interaction mechanisms (innovation in gaze-based interaction). MASTER will also deliver rich training content on robotics. MASTER proposes integrating third party contributions through two Open Calls: The first one aims to provide the platform with additional technologies and functionalities. The selected companies will have the opportunity to integrate their technology in the platform and test it with a wide range of end-users. The second Open Call is aimed at the education sector, by offering the possibility to test first-hand the platform and tools to create their own content.