HD DVD
HD DVD was the losing format in the high definition wars that lasted from 2006 to early 2008 (which were won by Blu-Ray). It was supported by Toshiba and NEC and has the same resolution as, and somewhat less storage than, Blu-ray. For a period of two years stores that sold video disks had to have two separate displays; HD DVD disk cases were similar to Blu-Ray but with reddish brown plastic at the top instead of blue. Some titles included both DVD and HD DVD versions, either as separate disks or as a hybrid format playable on both devices.
The DRM on HD DVDs did not include region coding, but did include the ability of the content owner to revoke keys such that an individual device can be prevented from playing any newer disks. The Internet erupted when a decryption key was leaked in 2007 and the MPAA and AACS LA, who control the licensing, tried to get the keys removed from the Internet, leading to the keys being spread even more.
The Xbox 360 briefly had an add-on that could play HD DVD disks, although games on the console did not use them.
An incompatible variant (CBHD) survives in China to this day and incorporates home-grown Chinese DRM and codecs.