This book presents an overview of dynamic combinatorial chemistry (DCC) and fragment-based library methods and how chemists apply them to the problems of lead generation for drug discovery and molecular recognition in bioorganic chemistry and materials science. Chapters cover basic theory, approaches to binding in proteins and small molecules, molecular recognition, catalyst discovery, click chemistry, "SAR by NMR," and analytical chemistry challenges. A single-source reference about modern methods in fragment-based drug discovery and DCC methods and applications, this is a core resource for chemists building structure libraries and designing compounds.