The medieval period was a time of important changes in Jewish book culture in the Muslim world. While book production and use were to some extent a continuation of ancient traditions, medieval Jewish readers discovered an array of unprecedented subjects and genres. Unlike anonymous or apocryphal transmission of antiquity, individual medieval authors strove to shape and control the circulation of their original works by fostering the notion of an “authorized” and “correct” text. Books took new physical forms and formats, used newly introduced book materials, and acquired a new status as sought after vehicles of scientific knowledge, pleasurable pastimes, or as prized collectors’ pieces. A book’s appearance depended on its cultural context but was also related to its intended destination: public use in a synagogue or a house of learning, a trophy acquisition for the library of a wealthy bibliophile, or for personal use as modest textbooks for scholars or schoolchildren. The reader and his capacity to make use of the books, his reading comfort, and his literacy and linguistic skills were all important considerations when a book was made.