http://cosmo.torun.pl/pipermail/cosmo-torun/
that the WMAP data should be readable using free software (free as in speech - http://www.gnu.org) and hence that having a non-free licence for the official healpix software package was not very constructive, it seems that the official group have finally accepted peer pressure and released their package under the GPL:
http://sourceforge.net/projects/healpix/ (version 2.00)
- click on download to download the package# License: GNU General Public License (GPL)
For anyone interested in what the healpix projection/pixelisation is all about, you can read the following three articles, chronologically:
- astro-ph/0409533
- astro-ph/0409513
- astro-ph/0412607 - updated version: http://www.atnf.csiro.au/people/mcalabr ... 0050615.ps
More importantly, in astro-ph/0412607 we point out that the healpix projection/pixelisation is a combined cylindrical equal-area projection + a Collignon (1865) projection, followed by the hierarchical pixelisation of 12 squares. (There's also a generalisation of this class of projections in the paper.)
And there are at least three independent GPL software packages:
- http://sourceforge.net/projects/healpix/ - the official group
- http://cosmo.torun.pl/GPLdownload/dodec ... .12.tar.gz - isolat - a tiny GPL autoconf'ed package, can be included as a fortran77 or C library in any GPL-compatible package, or can be used on the command line with standard gnu/linux type options
- ftp://ftp.atnf.csiro.au/pub/software/wc ... lib.tar.gz wcslib - a complement to the standard fitsio package
All's well that ends well.