Comparison of high definition optical disc formats Blu-ray disc players since the end of the format war. Blu-ray Disc has a higher maximum disc capacity than HD DVD (50 GB vs. 30 GB for a double layered disc). In September 2007 the DVD Forum approved a preliminary specification for the triple-layer 51GB HD DVD (ROM only) disc though Toshiba never stated whether it was compatible with existing HD DVD players. In September 2006 TDK announced a prototype Blu-ray Disc with a capacity of 200GB. TDK was also the first to develop a Blu-ray prototype with a capacity of 100GB in May 2005. In October 2007 Hitachi developed
Archival Disc data storage within the datacenter. Archival Disc Archival Disc (AD) is the name of a trademark owned by Sony Corporation and Panasonic Corporation describing an optical disc storage medium designed for long-term digital storage. First announced on 10 March 2014 and planned to be introduced in the second quarter of 2015, the discs are intended to be able to withstand changes in temperature and humidity, in addition to dust and water, ensuring that the disc is readable for at least 50 years. The agreement between Sony and Panasonic to jointly develop the upcoming generation optical media standard was first announced