This book is the first comprehensive review of chondrules and their origins since a consensus developed that they were made in the disk of gas and solids that formed the Sun and planets 4.5 billion years ago. Fifty scientists from assorted disciplines have collaborated to review how chondrules could have formed in the protoplanetary disk. When and where in the disk did they form? What were they made from and how fast were they heated and cooled? What provided the energy to melt chondrules--nebular shock waves, lightning discharges, protostellar jets? Following an exciting international conference in Albuquerque, New Mexico, the latest answers to these questions are presented in thirty-four articles, which will appeal to researchers in planetary science and meteoritics.