Unimog axles do that as was mentioned. Portal axles, and the ones ont he hummer are the same style. The rockwell is higher because the power input is at the top of the pumpkin, not roughly in the center.
Unimog, Portal, and Hummer axles all have an extra gear reduction at the hub that makes it so you can use smaller driveline pueces since the torque is not being multiplied as many times. For instance, your engine makes 200 ft/lbs. you have a 3.00:1 first gear, a 2:1 transfert case, and a 4.11:1 diff.
Your 200lb/ft turn into 4932 ft/lbs as soon as the power hits the axles. (200 x 3 x 2 x 4.11 =4932) Twist city. by moving that last 4.11:1 to end of the axle shaft, the axle shafts can be smaller. Since the last reduction is at the axles, the gear reduction takes up space, so the axle is offset. the designers decided to offset the axle upwards which means more space under the axle. Yay.