A fundamental understanding of coherent electromagnetic radiation processes, which is most rigorously based on quantum electrodynamics, is important for investigating the basic radiative interactions of condensed matter systems, relativistic free electrons in strong fields, and atomic systems in intense laser fields. There has been considerable recent interest in the investigation of coherent radiative interactions involving energetic electrons in crystal lattices, in spatially-periodic static-field structures (such as magnetic wigglers and undulators), and in electromagnetic fields (laser beams). There has also been current interest in radiation processes involving multiply-charged many-electron ions in high- temperature plasmas and in intense laser fields. The attention directed at these processes has been motivated in part by the need to assess various mechanisms for the generation of amplified spontaneous emission at short photon wavelengths (approaching the X-ray region). A precise theoretical treatment for these laser mechanisms and for other coherent electromagnetic radiation processes in the presence of strong fields will necessarily involve quantum-electrodynamics descriptions of the interaction between the electronic system and the electromagnetic field.