Researchers at a number of US universities review the current status of semiconductor nanostructure growth and materials development, and of semiconductor devices using nanostructures with a particular emphasis on three-dimensional nanostructures that have emerged during the past decade. They cover crystal, thin-film, and nanostructure growth technologies; quantum dot infrared photodetectors; the theory of quantum dot lasers; high-speed quantum dot lasers; nanostructures based on zinc oxide; antimony-based materials for electro-optics; growth, structures, and optical properties of III-nitride quantum dots; self-assembled Germanium nano-islands on silicon and potential applications; and carbon nanotube engineering and physics.