  Massive clusters are now seen to form easily in interacting and merging
galaxies, making these excellent environments for studying the properties of
young clusters. New observations of the Antennae (NGC 4038/39) show that the
most luminous young clusters do not have a measurable tidal radius. Most
observations suggest that the luminosity function (LF) and mass functions of
young clusters are single power laws. However, there are many uncertainties at
the faint end of the LF. For example, contamination from massive stars may be
important. The shape and evolution of the LF, and more fundamentally, the mass
function, of massive clusters had implications for our understanding of both
the formation and the destruction of massive stellar clusters.
