Disc, or Digital Versatile Disc, depending on whom you ask—is the next generation of optical disc storage technology. It’s essentially a bigger, faster compact disc that can hold video as well as audio and computer data. DVD aims to encompass home entertainment, computers, and business information with a single digital format, eventually replacing audio CD, videotape, laser disc, CDROM, and perhaps even video game cartridges. DVD has widespread—and unprecedented— support from all major electronics companies, all major computer hardware companies, and most major movie and music studios, which says much for its chances of success. The DVD Consortium, composed of 10 companies (Hitachi, JVC, Matsushita, Mitsubishi, Philips, Pioneer, Sony, Thomson, Time Warner, and Toshiba) developed DVD. Originally two competing formats existed: the Multimedia Compact Disc (MMCD) format backed by Sony, Philips, and others; and the Super Disc (SD) format backed by Toshiba, Matsushita, Time Warner, and others. A group of computer companies led by IBM insisted that DVD proponents agree on a single standard. The combined DVD format, announced in September of 1995, avoided a confusing and costly repeat of the VHS versus BetaMax videotape battle or the quadraphonic sound battle of the 1970s. After developing the specifications and standards, the Consortium changed its name to the DVD Forum and opened up membership. At the end of 1998 the DVD Forum had about 200 member companies. Unlike CD-ROM, which is a data storage format kludged from a digital audio format, DVD was built, from the ground up, as a complete family of formats based on a digital data storage foundation. DVD-ROM holds computer data read by a DVD-ROM drive hooked up to a computer. DVDVideo (often simply called DVD) is an application built on top of DVD-ROM. DVD-Video holds video programs played in a DVD player hooked up to a TV. The difference between DVD-ROM and DVD-Video resembles that between CD-ROM and audio CD, including the important point that DVD-Video discs can be played in computers. In addition to DVD-Video, which was introduced with DVD-ROM in late 1996, there exists an (as yet) unreleased DVD-Audio format, finalized in February of 1999. DVD-ROM also includes recordable variations (DVD-R, DVD-RAM, DVD-RW, and DVD+RW), some not yet available, and some subject to sibling rivalry. That is, some competing formats are incompatible. See Table 1. Most of the DVD format is proprietary to the DVD Forum. The official DVD specification books are available from Toshiba by signing a nondisclosure agreement and paying a $5,000 fee. Some portions of the DVD specification that specify physical disc characteristics were submitted to ECMA for standardization and can be downloaded for free at http://www.ecma.ch. Table 2 shows the capacities of each DVD type. The basic DVD-ROM format is covered in ECMA-267 and ECMA-268, DVD-R in ECMA-279, DVD-RAM in ECMA-272 and ECMA273, and DVD+RW in ECMA-274. The UDF file system specification used by all DVD formats is available from the Optical Storage Technology Association at http://www.osta.org. For standards used in DVD see the sidebar (page 88).