Blue Book (CD standard) Blue Book (CD standard) The Blue Book is a compact disc standard developed in 1995 by Philips and Sony. It defines the Enhanced Music CD format (E-CD, also known as CD-Extra, CD-Plus and CD+), which combines audio tracks and data tracks on the same disc. The format was created as a way to solve the problem of mixed mode CDs, which were not properly supported by many CD players. The standard is not freely available and must be licensed from Philips. E-CDs are created through the "stamped multisession" technology, which creates two sessions on a disc. The first session of
CD-i games from The Legend of Zelda series out to independent studios, Philips subsequently used the characters to create three games for the CD-i, with Nintendo taking no part in their development except to give input on the look of the characters based on the artwork from Nintendo's original two titles and that of their respective instruction booklets. Philips insisted that the development studios utilize all aspects of the CD-i's capabilities including FMV, high-resolution graphics, and CD-quality music. Because the system had not been designed as a dedicated video game console, there were several technical limitations, such as laggy controls (especially for the standard infrared controller), and numerous