This report examines the potential impact of optical media--videodiscs, compact audio discs, and optical disks, tapes, and cards--in library related applications. A detailed consideration of the technology includes discussion of the underlying principles, the various forms in which the technology is marketed, production methods and costs, and the capabilities of each different medium. An introductory chapter outlines the different forms of optical media and their potential applications in libraries. Each of the remaining 11 chapters then addresses the details of one of the following technologies: videodiscs; interactive videodiscs; recording digital data on videodisc; videodisc production; compact audio discs and CD ROM (compact disc read only memory); videodiscs and CD ROM as digital publishing media; optical digital discs; optical digital products; and erasable optical media. A number of video and compact audio disc projects currently being developed or investigated in library settings are examined in the appropriate chapters, including audio and video applications at Video Patsearch, the National Library of Canada, the National Library of Medicine, and the Library of Congress; digital data publishing projects at MiniMARC, Information Access Corporation, Carrollton Press, the Library Corporation, and other companies; and library applications of optical digital disk technology at the Library of Congress, the National Library of Medicine, the National Air and Space Museum, the Public Archives of Canada, and Disclosure Information Group. An appendix explains the process of converting text, graphics, and audio to digital form. (THC)