The operation of the experimental storage ring ESR with beams of highly charged heavy ions has been studied at GSI over more than a decade. Beam cooling, either stochastic or by electrons, and internal gas jet target have been applied routinely. The conceptual design of a new storage ring complex at GSI is based mainly on experimental data for equilibrium beam parameters and cooling times measured at that ring. The generation of intense rare isotope beams is one of the pillars for the proposed GSI Future Project (http://www.gsi.de/GSI-future/project) which makes use of the existing UNILAC/SIS18 as injector for a new 100 Tm-synchrotron, SIS100. Especially nuclear physics experiments with stored and cooled rare isotope beams at essentially increased beam intensities will deliver important information on properties and structure of nuclei far from stability.