This book introduces a recent development in the theoretical research into the dynamic behaviour of fracture. This field is really a new trend in mechanical engineering and because of the interdisciplinary applications, physicists and materials scientists are also interested in the subject. The book has a review paper and about 20 high-level contributions. The main benefit to the reader is in showing how the recent development of molecular dynamics and other state-of-the-art methods can really solve the important problem of fracture from the atomic level.