Backed by Toshiba and friends, HD DVD lost a battle that ran most of the decade to be the format for high-definition video disks. Sony and its movie studio pushed Blu-ray in an echo of the fight over Betamax and VHS tape formats, except that Sony lost that one. HD DVD actually had the early lead over Blu-ray, but movie studios eventually sided with the Sony group. Blu-ray is selling more players this holiday season (some can be bought for $100 or less). But the nasty format fight cost high-def disks crucial time in trying to be the successor to DVD, and Blu-ray faces growing competition from Internet downloads.