An optical disk format. Developed by a consortium of over 180 companies led by Sony, Blu-ray disks are to intended to supercede the DVD both for the distribution of video and for data storage – Blu-ray disks can hold up to 25 Gb on each of up to two layers. Like its rival HD DVD format, it achieves this greater capacity by using a “blue”(actually, a violet) laser rather than the red laser used for DVDs; the shorter wavelength allows the beam to be focused more precisely and so more data to be packed into a given space. Currently (2008) some high-definition DVDs have been released in Blu-ray format, and computer Blu-ray drives are becoming available. The prospects for Blu-ray were considerably enhanced by the effective demise of HD DVD in early 2008.