Continuing the focus of the series on basic science rather than applications, 29 papers from a workshop in Cambridge, England, in July 2000 report on recent research into phase transitions in both ordered and disordered material. They emphasize new concepts in network glasses, simple mechanical systems in which new phenomena have been discovered as a result of exploring stiffness transitions both experimentally and in numerical simulations; the metal-insulator transition in semiconductor impurity bands, where an intermediate phase has also been identified; and mostly cuprate perovskites, where an intermediate phase occurs that can have superconductive transition temperatures well above 100 Kelvin.