Progress since 1955 in the technology of zirconium and its alloys is reviewed primarily from an applications viewpoint. A number of favorable features have been uncovered as their use broadened as well as problem areas which required accommodation in design or lifetime. Zirconium technology has reached its present stage of development as a result of world-wide contributions. The original paper was published by ASTM International in STP 681, Zirconium in the Nuclear Industry (Fourth Conference), 1979, pp. 5–18.