IAU Symposium 272 presents an overview of the latest research into active OB stars. These massive, volatile objects serve as test beds for extreme conditions, and research into them has entered a new era with the advent of new space and round-based instrumentation. In this volume, renowned experts discuss the cutting-edge observations, state-of-the-art modeling and recently developed techniques such as asteroseismology, interferometry and spectropolarimetry that have improved our understanding of these extreme objects. Asteroseismology allows us to infer the internal structure of massive...