I am very keen to have a Mathematica version of HEALPix. I have written some code, but only a very minor subset of what is in HEALPix.
There is a Matlab version (mealpix) at Penn State. I have looked at it and it could be used as a guide. My impression is that a full working version would take a large investment of time, but would be valuable. Perhaps someone could persuade Wolfram to take it on.
