Medical robotics, computer- assisted surgery (CAS), image-guided therapy (IGT), and the like emerged more than 20 years ago, and many advances have been made since. Conferences and workshops have been organized; scientific contributions, position papers, and patents have been published; new academic societies have been launched; and companies were created all over the world to propose methods, devices, and systems in the area. Researchers in robotics, computer vision and graphics, electronics, mechanics, biomedical engineers, physicians, and surgeons have been involved, thus demonstrating the enthusiasm for this emerging field. Their commitments emphasize the transdisciplinary nature of the efforts to be made. However, the effective dissemination of CAS-IGT systems in medical disciplines remains limited. There are several reasons that may explain this situation, among which the effective demonstration of patient benefits and cost savings, the reluctance of surgeons or therapists to use them, and, of course, the technological breakthroughs are still expected. This series of articles attempts to point out some of them and will also show that many opportunities in computer-assisted interventions are open in the near future.