Definition: HD-DVD is one of two major High Definition DVD formats (the other format is Blu-ray) that were vying to replace the DVD standard in the U.S. market. HD-DVD was supported on the hardware side by Toshiba, NEC, Sanyo, Thomson (Note: Thomson also supports Blu-ray). On the software side, HD-DVD was supported by New Line Cinema, Paramount Pictures, and Universal Pictures. Microsoft also aded its support for HD-DVD. However, in February 2008, HD-DVD was discontinued. As a result HD-DVD players and discs are no longer being manufactured, but there is still a viable secondary market.