Research on massive stars is undergoing a period of rapid progress, with long-held convictions being shown to be incomplete. While these stars are relatively few in number, they are the main driver of chemical and dynamical evolution in galaxies through their stellar winds and explosive deaths in core-collapse supernovae. Furthermore the impact of massive stars is widely recognized in many areas, as they are often used as tools to interpret the conditions and processes arising in different environments. In parallel, the development of new instrumentation, analysis techniques and dedicated surveys across all possible wavelengths have delivered large amounts of exquisite new data. These data are now providing a harsh test for the current state-of-the-art theoretical calculations of massive star birth, evolution and death. IAU Symposium 329 covers these topics and is therefore an invaluable resource for researchers in the field of massive stars and their evolution.