Intel and Microsoft have announced their support for the HD-DVD format, citing its "unique advantages" over Blu-Ray such as affordability and an earlier estimated launch date.
"After looking at the core advantages to the PC ecosystem and how it would benefit the consumer, it is clear that HD-DVD offers the highest quality, and is the most affordable and highly flexible solution available," said Microsoft's Blair Westlake.
Intel technology officer Brendan Traw added: "Intel has determined that HD DVD best meets the needs of consumers and the requirements for the respective consumer electronics, computer and entertainment industries for delivering a high-definition, interactive experience to the home."
Up until now, both Intel and Microsoft have officially remained neutral in the HD-DVD vs. Blu-Ray battle, declining to take part in the negotiations between Sony and Toshiba over a possible unified format. The fact that they have finally picked a side suggests that any remaining glimmer of hope has now disappeared.
It's no great surprise that Microsoft has joined the HD-DVD camp - just last month, the Redwood giant was rumoured to be considering incorporating HD-DVD technology into future versions of the Xbox 360.
Other companies who have already announced their support for the format include NEC, Sanyo and Hitachi, along with movie studios Universal, Warner Bros. and Paramount. Blu-Ray backers include Apple, Philips, Hewlett-Packard, Twentieth Century Fox and Buena Vista Home Entertainment.
Toshiba's supporters argue that HD-DVD discs are less expensive and easier to produce - making them cheaper for the consumer. HD-DVD discs can also hold high definition data on one side and standard definition on the other for backwards compatibility.
But single layer Blu-Ray discs can hold up to 30Gb, while dual layer discs can hold 50Gb - compared to just 15Gb and 25Gb respectively for HD-DVD discs. Blu-Ray also has an advantage in that Sony's PlayStation 3 will use Blu-Ray technology, making for a sizeable installed user base when the console launches.
Sony's backers responded nonchalantly to the announcement from Microsoft and Intel, with Hewlett-Packard executive and Blu-Ray spokesman Josh Peterson commenting: "We don't see this announcement as anything that will shift the momentum that Blu-Ray disc has experienced."