The performance of structural materials is commonly associated with such design parameters as strength and stiffness relative to their density; a recognized means to further enhance the weight-saving potential of low-density materials is thus to improve on their mechanical attributes. The European Community research project ExoMet that started in mid-2012 targets such high-performance aluminum- and magnesium-based materials by exploring novel grain refining and nanoparticle additions in conjunction with melt treatment by means of external fields (electromagnetic, ultrasonic, and mechanical). These external fields are to provide for an effective and efficient dispersion of the additions in the melt and their uniform distribution in the as-cast material. The consortium of 27 companies, universities, and research organizations from eleven countries integrates various scientific and technological disciplines as well as application areas-including automotive, aircraft, and space. This paper gives an overview of the project, including its scope for development and organization. In addition, exemplary results are presented on nanoparticle production and characterization, mixing patterns in metal melts, interface reactions between metal and particles, particle distribution in the as-cast composite materials, and mechanical properties of the as-cast composite materials. The application perspective is considered as well. (C) The Minerals, Metals & Materials Society and ASM International 2014