The latest version of the CFITSIO source code, documentation, and example programs are available on the Web or via anonymous ftp from:
Any questions, bug reports, or suggested enhancements related to the CFITSIO package should be sent to the FTOOLS Help Desk at the HEASARC:
This User's Guide assumes that readers already have a general understanding of the definition and structure of FITS format files. Further information about FITS formats is available from the FITS Support Office at http://fits.gsfc.nasa.gov. In particular, the 'FITS Standard' gives the authoritative definition of the FITS data format. Other documents available at that Web site provide additional historical background and practical advice on using FITS files.
The HEASARC also provides a very sophisticated FITS file analysis program called `Fv' which can be used to display and edit the contents of any FITS file as well as construct new FITS files from scratch. Fv is freely available for most Unix platforms, Mac PCs, and Windows PCs. CFITSIO users may also be interested in the FTOOLS package of programs that can be used to manipulate and analyze FITS format files. Fv and FTOOLS are available from their respective Web sites at: