The chapters in this volume present the state of optimum experimental design at the beginning of the new millennium, with an emphasis on developing areas. The contributions range from theory to applications, starting with a glimpse back to the beginnings of optimum experimental design. Theoretical chapters cover the properties and methods of construction of designs. Applications include chapters on sequential design problems in the pharmaceutical industry and on the designs with discrete factors in agriculture. There are chapters on training neural networks, on the efficient selection of sampling methods, and on problems arising in glass making and in herbicide resistance of Brazilian weeds. The contributors, from a variety of countries, include many acknowledged experts whose work reflects the international spread of activity in the subject. Audience: Experimentalists as well as research workers and students in statistics will find much to interest them in these papers.