Recent advances in computational power are now enabling scientists to consider problems of population dynamics at an advanced level. The small bodies of our solar system, the planets around other stars, dust belts, space debris, etc., need to be understood as a a whole, with their collective dynamical evolution, stability and instability, order and chaos, aggregations and impacts. Important results on specific populations of celestial bodies, in addition to new methods of computation and analysis, have been obtained in the last few years. Scientists from 21 countries convened for the Colloquium "Dynamics of Populations of Planetary Systems", sponsored by the International Astronomical Union, in Belgrade (Serbia and Monte Negro). This proceedings volume reviews current understanding of the field, and is a valuable resource for professional astronomers and planetary scientists.