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
The Legend of Zelda was developed and released for the Philips CD-i in the early 1990s as a product of a compromise between Philips and Nintendo, after the companies failed to develop a CD-ROM peripheral for the Super NES. Created independently with no observation by or influence from Nintendo, the games are , together with "Zelda's Adventure". Nintendo never acknowledged them in the "Zelda" timeline, and they are considered to be in a separate, self-contained canon. These games are widely acknowledged to be the worst installments in the series. Three "Zelda"-themed LCD games were created between 1989 and 1992. The "Zelda" version of Nintendo's