The widely-held view that pulsed sources and reactors are complementary, the former producing epithermal neutrons and the latter cold neutrons, has been shown in recent years to be an oversimplification. The concept of complementarity, if in fact it exists, is one of methods rather than of sources, frequently allowing similar scientific topics to be examined in refreshingly different ways. As more experience is gained in the still unfolding new methods of pulsed neutron scattering, it is clear that no area can sensibly be excluded from investigation using pulsed sources. It is also crucial to realize that the body of knowledge is changing rapidly with time. The boundaries are not constant and the horizon has not yet been seen.