Book excerpt: The synthesis of macrocycles is an art in itself. Template-controlled synthesis provides elegant access to fascinating macrocyclic structures. Polyazamacrocycles, crown ethers, cryptands, rotaxanes, knots -- the range of macrocyclic compounds is as broad as their potential application as molecular switches, in ion exchange, electron transfer or catalysis. This book provides authoritative information on all aspects of template-controlled macrocyclizations. It covers in depth the current state of research on template processes - novel synthetic techniques and mechanistic approaches. The critical discussion of the diverse synthetic routes includes the detailed characterization of the broad variety of macrocyclic products. References to applications of macrocyclic compounds and over 1,500 citations make this handbook an indispensable tool for chemists in academia and industry. Researchers in organic and supramolecular chemistry, biotechnology, and inorganic chemistry will find inspiration for the design, synthesis, and myriad uses of new synthetic macrocycles.