A number of programs and subroutine libraries are available for manipulating the files used by XSPEC. Most of these are part of the FTOOLS package of tasks to read, write, and modify FITS-format files. There are a few tasks in the XANADU distribution for manipulating the older pre-FITS file formats. However, we recommend that you use the FTOOLS conversion tasks to turn older files into the FITS format and then use the FTOOLS tasks to manipulate them.
The FTOOLS package is available at ftp from