The study of molecular clouds has received increasing interest over recent years, particularly in the UK with the advent of powerful new instruments such as MERLIN and the Maxwell millimetre wave telescope. This book is based on the proceedings of the Seventh Manchester International Astronomy Conference which brought together an international list of speakers to discuss important new developments in this field. The book covers a wide range of topics relevant to the general subject of molecular clouds, with review articles and papers from an impressive list of contributors. Much new work in this area is covered, and consequently this book should become an important reference source for workers in this and related fields.