This volume describes methodology for the long-term preservation of all kinds of digital documents. It outlines a technical solution and justifies its correctness and optimality. The 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 the title explains the requirements of the related software and sketches how to implement it. The book is ideal for Archivists research librarians and museum curators; 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.