This session will cover recent progress in understanding structure and properties of glass under extreme conditions, such as high pressure, high stress, high temperature, high radiation, highly reactive conditions, etc. Many manufacturing processes such as fiber drawing, laser writing, and irradiation aging are concerned with these conditions. New knowledge of glass structure and properties under extreme conditions can help design glass for these applications, as well as in utilizing such conditions to synthesize glass with superior properties. Experimental studies, novel in situ analysis methods, and computational approaches are within the scope of this session.