AbstractThis review starts with a brief historical overview of the subject, after which some recent papers attempting to improve the understanding of comet injection from the Oort Cloud and the origin of new comets are discussed. Special attention is paid to the importance of nongravitational effects in comet orbit determination, the synergy between stellar encounters and the galactic tides for the injection dynamics, and the role of planetary perturbations. The field is thus shown to be advancing rapidly, and brief comments on possible implications for studying the origin of the cloud are made.