Microsoft stepped up to deliver iHD (later renamed HDi), which was a trademarked implementation of HD DVD's XML markup language. Toshiba liked it. They made HDi functionality a standard for HD DVD players, and eventually partnered with Microsoft to expand HDi's reach by founding the Advanced Interactivity Consortium. The primary goal of this group was forging industry relationships to further promote HDi in emerging outlets like downloadable and streaming media.
The deal gave HD DVD its competitive next-gen features, but here's the rub: Microsoft didn't need physical media to implement HDi. All of HDi's interactive bells and whistles could theoretically be applied to downloadable video content, as long as a runtime environment was available. Even as the disc format war raged on, elements of HDi's runtime environment showed up in Microsoft products like the Xbox 360 and Vista.
So, let's put everything together. Microsoft has a popular gaming console and an operating system that are HDi compatible. It also has a group of developers working on HDi applications, and a 360-accessible HD video library that could feasibly be outfitted with next-gen interactivity features. All that's left is the dog and pony show needed to convince content providers that HDi-enhanced content and Microsoft's video outlets are key to making HD video downloads a viable revenue stream. http://www.thestandard.com/news/2008...u-ray-xbox-hdi