Book excerpt: This book focuses on new small molecule approaches to combat viral infections. The chapters describe the discovery and development from bench through the clinic of relatively recently-approved antiviral drugs and compounds in advanced clinical development. Organized by a virus (such as HIV, HCV, RSV, influenza, HBV and CMV) and written by top academic and industrial authorities in the field, the book provides a unique opportunity to study, understand and apply discovery and development principles and learning without the need for an individual to research, analyze and synthesize all immense sourcing references. Topics showcase challenges and solutions of issues encountered, offering tremendous experience accumulated over many years of research that will be particularly useful to basic and bench scientists as well as clinicians as they continue discovering and developing new drugs and therapies.