There is abundant evidence that essentially all luminous hot-star winds contain time-dependent and anisotropic structures. IAU Colloquium 169 was convened to review the observations of variability and asphericity, to discuss the physical processes that might cause such behavior and to look for evolutionary consequences. The topics included OBA stars, Be stars, Wolf-Rayet stars, Be stars, and luminous blue variables (LBVs). The role played by rotation in shaping the stellar wind was a recurrent theme. Photospheric pulsations and/or magnetic fields are particularly appealing mechanisms for triggering the formation of recurrent wind structures.

There is abundant evidence that essentially all luminous hot-star winds contain time-dependent and anisotropic structures. IAU Colloquium 169 was convened to review the observations of variability and asphericity, to discuss the physical processes that might cause such behavior and to look for evolutionary consequences. The topics included OBA stars, Be stars, Wolf-Rayet stars, Be stars, and luminous blue variables (LBVs). The role played by rotation in shaping the stellar wind was a recurrent theme. Photospheric pulsations and/or magnetic fields are particularly appealing mechanisms for triggering the formation of recurrent wind structures.