Spin glasses exhibit random magnetic ordering as a result of competing interactions such as exchange or anisotropy. While they are easily prepared, and many of their general properties have been described, a detailed understanding of their behaviour is still lacking after more than 30 years of study. This book reviews the progress that has been made over the last five years on several aspects of the spin glass problem. Unlike several recent books, the authors concentrate here on experimental results, limiting the theoretical discussion to efforts most directly related to such work. The field of spin glasses, or more generally random magnets, continues to attract the interest of researchers worldwide, and the contributions in this book clearly show that this will be the case for many years to come.