The Compact Disc-Interactive (CD-I, later CD-i) is a digital optical disc data storage format that was mostly developed and marketed by Dutch company philips. It was created as an extension of CDDA and CD-ROM and specified in the Green Book, co-developed by philips and sony, to combine audio, text, and graphics. The two companies initially expected to impact the education/training, point of sale, and home entertainment industries, but CD-i eventually became best known for its video games.
CD-i media physically have the same dimensions as CD, but with up to 744 MiB of digital data storage, including up to 72 minutes of full-motion video. CD-i players were usually standalone boxes that connect to a standard television; some less common setups included integrated CD-i television sets and expansion modules for personal computers. Most players were created by philips; the format was licensed by philips and Microware for use by other manufacturers, notably sony who released professional CD-i players under the "Intelligent Discman" brand. Unlike CD-ROM drives, CD-i players are complete computer systems centered around dedicated motorola 68000-based microprocessors and its own operating system called CD-RTOS, which is an acronym for "Compact Disc – Real-Time Operating System".
Media released on the format included video games and "edutainment" and multimedia reference titles, such as interactive encyclopedias and museum tours – which were popular before public Internet access was widespread – as well as business software. philips's CD-i system also implemented Internet features, including subscriptions, web browsing, downloading, e-mail, and online play. philips's aim with its players was to introduce interactive multimedia content for the general public by combining features of a CD player and games console, but at a lower price than a personal computer with a CD-ROM drive.
Authoring kits for the format were released first in 1988, and the first player aimed for home consumers, philips's CDI 910/205, at the end of 1991, initially priced around US$1,000 (equivalent to $1,877 in 2019), and capable of playing interactive CD-i discs, Audio CDs, CD+G (CD+Graphics), Karaoke CDs, Photo CDs and Video CDs (VCDs), though the latter required an optional "Digital Video Card" to provide MPEG-1 decoding. Initially marketed to consumers as "home entertainment systems", and in later years as a "gaming platform", CD-i did not manage to find enough success in the market, and was mostly abandoned by philips in 1996. The format continued to be supported for licensees for a few more years after.