Storage Management Strategies for the CIO
Double-Density Compact Disk (DDCD) is a CD format that increases the storage capacity of the disk through means such as increasing the number of tracks and pits (scores on the disk that are used to encode the data). Philips and Sony described the DDCD specifications in their 2000 document (known informally as the Purple Book).
Although DDCD did not receive much industry notice until Philips and Sony produced the Purple Book specifications, the Optical Disc Corporation (ODC) released a similar format, High Density CD (HDCD) in 1993, and Nimbus Technology and Engineering introduced their own Double-Density CD format in 1994. The general feeling in the industry is that DDCD has been introduced as a stop-gap measure to tide over the market until DVD inevitably solves its problems (such as standardization and compatibility issues) and makes the CD obsolete.