Some are.
There is a split in the gear ratios. 3.73 and up and 3.92 and down.
Ford, Chevy, Dodge, Jeep all interchange in there side of the split.
High or low pinion are the same.
IFS (TTB Ford) will work in standard D44, but not always the other way around. There is an added C-clip to hold the passenger side axle in place that is needed for the IFS.
Very new stuff. Anything "new" after about '04 and all bets are off. Jeep JK for example calls the rear axle a D44, but it is a heavy departure from it. Nothing interchanges with the old D44. Few others the same way.
Then a few oddballs. Isuzu used a D44 with a 4.33 gear but it is a thick gear to use the 3.73 and up carrier.
Some of the early D44 stuff is a coarse 10 spline axle instead of the common 30 spline. This is 50/early 60s car axle that I know of.