yeah, that's like .... a full year bump, and some change. yikes.

GSpot trusts the fourcc, and reports a video as whatever those are. They're encoder-settable and easy to change.

Way back then (pre-1.0 xvid) the xvid decoder was craptastic. So, the choice was use a craptastic decode filter for a nice and versatile codec, or use divx 5's decoder instead.

around 1.0, xvid's native decoder matured quite nicely, and everyone who was paying attention stopped encoding with pre-1.0 xvid. most of them stopped changing the fourcc bits, too, so that it'd correctly identify.

Mose encoders didn't use the "DIVX" (opendivx) fourcc, which left it open to be decoded by even more inferior opendivx filters, and instead tried to force divx5 playback with "DX50" (divx5). Which is why people thought it was divx5, and why why it doesn't identify as opendivx or xvid.