Controlled/living polymerization makes it possible to synthesize polymers of low polydispersity with a predefined molecular weight and specified chain architecture. Such polymers are desirable for a broad range of applications, including coatings, adhesives, and lubricants. Although living polymerization was first discovered in anionic polymerizations in 1956, several decades passed prior to the development of living polymerization techniques for carbocationic polymerization (1984) and ring-opening metathesis polymerization (1986). During the 1990s, several techniques were developed for controlled/living free radical polymerizations. The development of these techniques led to a dramatic increase in the number of research publications dedicated to improving the understanding of controlled/living polymerization mechanisms, the synthesis and characterization of novel polymer architectures, and the applications of these polymers. In fact, a search on the Web of Science shows that in the past 20 years the number of references to living or controlled polymerization in the literature has increased from 48 to 1594. Therefore, the publication of this book, which reviews the various living/controlled polymerization techniques developed to date and the synthesis of a wide range of polymer architectures, is certainly timely and provides a much-needed resource for chemical professionals working with polymers.