The development of modern excimer lamps (excilamps) is reviewed. These lamps provide high intensity ultraviolet (UV) of vacuum ultraviolet (VUV) radiation generated by decaying excimer complexes formed in various non-equilibrium discharges. Due to the absence of self-absorption in the plasma this process can be highly efficient and tolerates high power loadings. With different fill gases narrow-band radiation at various UV and VUV wavelengths can be obtained. Phosphor coatings can be used to obtain visible radiation. Cylindrical as well as flat planar configurations are used to provide high photon fluxes over large areas. The special characteristics of excimer lamps led to a number of novel applications for low-temperature materials processing (oxidation, deposition, annealing, etching, cleaning, micro-structuring) and to applications in photochemical purification of air and water using advanced oxidation processes (AOPs) based on O2 and H2O photolysis. Further applications are expected in analytical instrumentation.© (2004) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.