HD DVD had declined to say whether the 51 GB disc was compatible with existing drives and players. Specification 2.0 Part 1 (Physical Specification) for triple layer HD DVD had been approved in November 2007. At the CES 2007, Ritek revealed their high definition optical disc process that extended both competing high definition formats to ten layers, increasing capacity to 150 GB for HD DVD and 250 GB for Blu-ray Disc. A major obstacle to implementing this technology in either format (150 GB HD DVD will not be developed due to HD DVD's discontinuation) is that reader-writer technology available may not be
The Hitchhiker's Guide to the Galaxy Tertiary to Hexagonal Phases released on 2 October 2006 in the UK. This marks the first commercial release of any BBC radio programme in a 5.1 surround mix. The disc contains as extras: the full version of the Krikket Song, a photogallery, the original online and radio trailers, the appearance of the series on Pick of the Week, and thirty minutes of behind the scenes video in five short segments. Note that while the BBC online shop is still listing the disc as a DVD-Audio disc, their own image confirms that the disc is a lower-definition standard DVD-Video. . Since the opening of the