afni.nimh.nih.gov

The general recommendation around here is to use TORTOISE for all things diffusion, and you can see the updated instructions on the blog page you linked to for how to do the preprocessing. If there's something that TORTOISE doesn't do, a feature request could be made to add it.

More to your question: Vecwarp was written by Bob, and he's away at a Bootcamp for the next week.