  [Abridged]: We present a database of structural and dynamical properties for
153 spatially resolved star clusters (50 "young massive clusters" and 103 old
globulars) in the Milky Way, the Large and Small Magellanic Clouds, and the
Fornax dwarf spheroidal. This database complements and extends others in the
literature, such as those of Harris, and Mackey & Gilmore. By fitting a number
of models to the clusters' density profiles, we derive various characteristic
surface brightnesses and radii; central potentials, velocity dispersions, and
escape velocities; total luminosities, masses, and binding energies;
phase-space densities and relaxation timescales; and ``kappa-space''
parameters. Population-synthesis models are used to predict intrinsic (B-V)
colors, reddenings, and V-band mass-to-light ratios for the same 153 clusters
plus another 63 globulars in the Milky Way, and we compare these predictions to
the observed quantities where available. These results are intended to serve as
the basis for future investigations of structural correlations and the
fundamental plane of massive star clusters, including especially comparisons
between the systemic properties of young and old clusters. We also address the
question of what structural model fits each cluster best, and argue that the
extended halos known to characterize many Magellanic Cloud clusters may be
examples of the generic envelope structure of self-gravitating star clusters,
not just transient features associated strictly with young age.

Astrophysics