In their Feature Article on pp. 375–383, Hvam, Stobbe and Lodahl discuss how the spontaneous emission from quantumdot (QD) excitons is influenced by the environment in which the QD is placed. Carefully chosen and well controlled nanostructured environments are in the first place used to determine fundamental QD-exciton parameters. Secondly, it is shown how the environment can be designed to enhance and control the emission. The cover figure illustrates the control of a QD single-photon emission into a photonic crystal membrane waveguide (artist's view).