Funnily enough the format war is why I know about it, since I decided to do a good long look into the pros and cons of each format, especially in terms of backwards compatibility and format support. HD DVD actually had an advantage in that regard: Blu-Ray only supports 480p and up, whereas HD DVD mandated support for damn near every resolution used by an existing disc-based format (VCD, SVCD) from 240p up. HD DVD players were also supposed to support content burned to CDs as well, meaning you could fit a fair chunk of lower resolution highly compressed HD DVD content on a CD and have it play in any HD DVD player, with subtitles and the like even.
Not really that relevant now obviously, but at the time I was kinda bummed that HD DVD didn't win the format war.