HD DVD

HD DVD or High-Definition/Density Digital Versatile Disc is an obsolete high-density optical disc format for storing data and high-definition video.HD DVD was designed principally by Toshiba, and was envisaged to be the successor to the standard DVD format. However, in February 2008, Toshiba abandoned the format, announcing it would no longer develop or manufacture HD DVD players or drives[1].

HD DVD is derived from the same underlying technologies as DVD. Since all variants except the 3× DVD employed a blue laser with a shorter wavelength, it can store about 3¼ times as much data per layer as its predecessor (maximum capacity: 15 GB per layer instead of 4.7 GB per layer).

Much like the VHS vs. Betamax format war during the late 1970s and early 1980s, HD DVD was in a "format war" with rival format Blu-ray Disc to determine which of the two formats would become the leading carrier for high-definition content to consumers. In 2008, major content manufacturers and key retailers began withdrawing their support for the format. Toshiba's withdrawal from the format ended the high definition optical disc format war, effectively making rival Blu-ray Disc the dominant format for high definition video discs.
The HD DVD Promotion Group was dissolved on 28 March 2008.
In the mid 1990s, commercial HDTV sets started to enter a larger market. However, there was no cheap way to record or play back HD content. There was no cheap storage medium that could store that amount of data, except JVC's Digital VHS and Sony's HDCAM.However, it was well known that using lasers with shorter wavelengths would yield optical storage with higher density. When Shuji Nakamura invented practical blue laser diodes, it was a sensation, although a lengthy patent lawsuit delayed commercial introduction.Launch

On March 31, 2006 Toshiba released their first consumer-based HD DVD player in Japan at ¥110,000 (US$934),beating Blu-ray to the market by about three months.HD DVD was released in United States on April 18, 2006,with players priced at $499 and $799.
The first HD DVD titles were released on April 18, 2006. They were The Last Samurai, Million Dollar Baby, and The Phantom of the Opera by Warner Home Video and Serenity by Universal Studios.The first independent HD film released on HD DVD was One Six Right.
HD DVD competed primarily with Blu-ray Disc. Both formats were designed as successors to DVD, capable of higher quality video and audio playback, and of greater capacity when used to store video, audio, and computer data. Blu-ray and HD DVD share most of the same methods of encoding media onto disks with each other, resulting in equivalent levels of audio and visual quality, but differ in other aspects such as interactive capabilities, internet integration, usage control and enforcement, and even in the degree to which their specifications are fixed. The storage size also varies: A dual-layer HD DVD holds a maximum of 30 GB of data, while a dual-layer Blu-ray carries 50 GB.