This volume celebrates the eightieth birthday of the famous applied mathematician Joseph B. Keller. The book contains 12 chapters, each on a specific area of mathematical modeling, written by established researchers who have collaborated with J.B. Keller during his long career. These chapters, all inspired by J.B. Keller, deal with a variety of application fields and together span the broad subject of mathematical modeling. The models discussed in the book describe the behavior of various systems such as those related to finance, waves, microorganisms, shocks, DNA, flames, contact, optics, fluids, bubbles and jets. The book also contains a preface written by the Editors, a full list of J.B. Keller's publications, and a comprehensive index. The book is intended for mathematicians, scientists and engineers, as well as graduate students in these fields, who are interested in mathematical models of physical phenomena.