File extension EVO is associated with HD DVD video file.HD DVD (short for High-Definition/Density DVD) is a discontinued high-density optical disc format for storing data and high-definition video. HD DVD was supported principally by Toshiba, and was envisaged to be the successor to the standard DVD format. However, in February 2008, Toshiba abandoned the format, announcing it would no longer develop or manufacture HD DVD players or drives.