I am enormously grateful to all of authors who have contributed to this volume on gas– liquid foam. One of the great pleasures of working with such accomplished scientists and engineers from industry and academia is that everybody has known the level at which to pitch their contributions. Special thanks are due to Laurie Schramm who, along with co-authors, has contributed two chapters on foams in enhanced oil recovery and flotation of oil sands, and to Thomas Martin who endured initial confusion upon my part to produce a first class chapter on firefighting foams
