The Electronic Book format was introduced by Sony to provide a standard method for publishers to record text, graphics and sound information on 8cm CD ROM discs. A given Book or Volume can support any or all of these methods.
Graphical menus are available on many Books.
Tray type CD-ROM drives typically support the 8cm discs on the tray itself. For caddy based 12cm drives, the widely available 8cm adapter can be attached to the disc and then inserted into the 12cm caddy. The adapter is included with the software. There are over 100 publishers supporting the EB format in Japan. Portable EB players are now being manufactured by Sony and Kyushu Matsushita.