Results important for the general understanding of nuclear structure have emerged from the study of the nuclei in the mass region around the neutron-deficient and neutron-rich Zirconium isotopes. This research report gives the proceedings of a workshop which brought together about 70 experts in the area. Review papers deal with the theoretical interpretation of the unusual properties of these medium-mass nuclei, using the mean field approach, a microscopic description, the interacting boson model and particle rotor calculations. Papers also discuss experimental procedures for studying nuclei far from stability and the possibility of complete spectroscopy. The reviews are supplemented by short contributions presenting very new results. Phenomena discussed include the interplay between subshell effects and the strong proton-neutron interaction in determining nuclear shape, the coexistence of different nuclear shape and the occurrence of fast beta decay.