The radio‐frequency (rf) driven multicusp source was originally developed for use in the Superconducting Super Collider injector. It has been demonstrated that the source can meet the H−beam current and emittance requirements for this application. By employing a porcelain‐coated antenna, a clean plasma discharge with very long‐life operation can be achieved. Today, the rf source is used to generate both positive and negative hydrogen ion beams and has been tested in various particle accelerator laboratories throughout the world. Applications of this ion source have been extended to other fields such as ion beam lithography, oil‐well logging, ion implantation, accelerator mass spectrometry and medical therapy machines. This paper summarizes the latest rf ion source technology and development at the Lawrence Berkeley National Laboratory. ©1996 American Institute of Physics.