Single photon emission, detection and manipulation will be explored on the basis of a novel semiconductor technology platform. By using semiconductor nanostructures like quantum dots and high-Q microcavity pillars or high-Q photonic crystal cavities, the interaction of individual photons with quantised electronic systems can be strongly enhanced to allow a full control of light generation, detection and manipulation at the single photon level. Within the framework of the project major building blocks of future single photon systems will be developed and explored. The consortium combines leading European research laboratories from universities, public research institutes and the industry with complementary expertise in nanostructure technology, optoelectronic devices and quantum physics. The project is expected to have a large impact on different areas of optical data communication (e.g. quantum cryptography) and on-chip data processing (like highly integrated single photon circuits). Several key devices, such as single photon emitters, single photon detectors as well as optical buffers, will be demonstrated.