It is now a well-established tradition that every four years, at the end of winter, a group of ''celestial mechanicians'' from all over the world gather in the Austrian Alps at the invitation of R. Dvorak. This time the colloquium was held at Badhofgastein from March 19 to March 25, 2000 and was devoted to the ''New Developments in the Dynamics of Planetary Systems''. The papers covered a large range of questions of current interest: t- oretical questions (resonances, KAM theory, transport, ... ) and questions about numerical tools (synthetic elements, indicators of chaos, ... ) were particularly well represented; of course planetary theories and Near Earth Objects were also quite popular. Three special lectures were delivered in honor of deceased colleagues whom, to our dismay, we will no longer meet at the ''Austrian Colloquia''. W. Jefferys delivered the Heinrich Eichhorn lecture on ''Statistics for the Twenty-first Century Astrometry'', a topic on which Heinrich Eichhorn was a specialist. A. Roy delivered a lecture honoring Victor Szehebely on ''Lifting the Darkness: Science in the Third Millenium'', in which in wove anecdotes and remembrances of Victor which moved the audience very much. A. Lemaitre spoke in honor of Michele Moons on ''Mech anism of Capture in External Resonance''. The end of her talk was devoted to a short and moving biography of Michele illustrated by many slides.
