Cultural history enthusiasts have asserted the urgent need to protect digital information from imminent loss. Without action, much of what has been created in digital form is likely to become unusable. Although a decade has already elapsed since this challenge was clearly articulated, nobody has described a complete procedure for preventing such loss – until now. Leading industry consultant Henry M. Gladney outlines a technical solution and justifies its correctness and optimality. His presentation focuses on long-term digital preservation principles as a basis for producing the software that will be needed. The method described will work for any kind of digital document, multimedia file, business record collection, or scientific information, and is believed to be optimal with respect to both the quality of the preserved information and end-user convenience. Additionally, Dr. Gladney explains the requirements of the related software, and sketches how to implement it. Preserving Digital Information presents an up-to-date description of its field, together with a solution for all technical problems identified in the pertinent professional literature. It is for archivists, research librarians, and museum curators who need to understand digital technology in order to manage their institutions; software engineers and computer scientists whose work requires sound information about digital preservation; and attorneys, medical professionals, government officials, and business executives who depend on the long-term reliability of digital records.