The early scientific and technical discoveries in zeolite synthesis and catalysis of a handful of researchers, Milton, Breck, Rabo, and Flanigen, among others, blossomed into a global industrial enterprise during the second half of the twentieth century. Zeolites and their unique properties have had a major impact on the world, and have directly or indirectly affected everyone alive today. Both the scientific and industrial interest in zeolites continues unabated at the dawn of the 2 1 st century, as new zeolites continue to be discovered in laboratories around the world. Patent activity continues to grow in areas utilizing zeolite materials. International technical conferences devoted to zeolite science are numerous and growing. The demand for new materials and associated novel properties and for novel catalytic routes will continue well into the rest of this century.