With the discovery of the planets orbiting other stars we now continuously improve our basic concepts on planetary dynamics. The discovered worlds challenge our imagination by their unusual orbital configurations and raise new questions in our understanding of their origin and dynamical evolution. For centuries paradigm, with clock-working revolution of the low-eccentricity and low-inclination planets, our own Solar System emerges now as an atypical structure in the current sample of the 21 known multi-planetary extra-solar systems.

The understanding of the planetary dynamics is receiving particular attention for several reasons. These include: 1) Detection of the extra-solar planets and determination of their orbits. 2) Long-term evolution and stability of the extra-solar systems. 3) The theories of formation/migration of the planetary systems. 4) Planetary habitability studies, search for life.