The Kinematic Models for Design Digital Library (K-MODDL) is a collaborative effort of Cornell University librarians and faculty in Mechanical Engineering and Mathematics to provide open access, multimedia resources for learning and teaching about Kinematics. The website provides an overview of Kinematics, which is "the geometry of pure motion," along with a discussion of its history and contribution to a theory of machines. Funded by the National Science Digital Library of the National Science Foundation (NSF), K-MODDL is intended as "a pedagogical space" for use by teachers and researchers, and learners of all levels. The key feature of K-MODDL is the Reuleaux Collection of Mechanisms and Machines, which includes several interactive photographic animations and descriptions that illustrate kinematic mechanisms. Visitors may browse the models in the collection by category, or search by title words or by keyword (in English or German). Also available are educational tutorials, historical and contemporary texts related to the history and theory of machines and mechanisms, biographical information on important players in the history of machines and the field of kinematics, and finally, stereolithography files for “printing” working physical replicas.