High-power experiments with waves in the ion cyclotron range of frequencies (ICRF) have been performed on the DIII-D tokamak since 1988. In the course of these experiments, it has been necessary to carry out some development of the relevant technology. These developments, primarily in the areas of the plasma/antenna interface, high-power transmission line components, and transmission line configurations, are reviewed in this paper. They have led to a number of recommendations for specifying systems in next-generation tokamaks.