In this report, emphasis is placed on issues related to selection and design of high-temperature, ion sources that have demonstrated the high ionization efficiency, species versatility, and operational reliability required at ISOL based radioactive ion beam facilities. In designing sources for ISOL applications, careful attention must be given to the following: selecting the most appropriate materials of construction, coupling of the vapor transport system, ion optics, operational parameters, thermal transport properties, emittances, ionization efficiencies and engineering details for safe handling in the high-level radioactivity radiation fields incumbent at such facilities. Included in the article are descriptions and performance data for high temperature, positive (electron-impact and surface-ionization) and negative (kinetic-ejection and surface-ionization) ion sources, as well as, low temperature, batch-mode negative-ion sources, developed for processing long-lived isotopes, that have been principal contributors to recent successes held at the Holifield Radioactive Ion Beam Facility.