Book excerpt: This volume describes the latest developments in the design, construction and operation of cyclotrons, from compact machines producing intense beams for isotope production, cancer therapy and industrial use, to the larger versions giving higher energy beams of ions of various elements for nuclear and particle physics. Important topics include ECR ion sources, superconducting magnets and radiofrequency cavities, beam dynamics and diagnostics, beam cooling rings, control systems and various medical and industrial applications.