IRAF has the following copyright information:
Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
The IRAF software is publicly available, but is NOT in the public domain. The difference is that copyrights granting rights for unrestricted use and redistribution have been placed on all of the software to identify its authors. You are allowed and encouraged to take this software and use it as you wish, subject to the restrictions outlined below.
Permission to use, copy, modify, and distribute this software and its documentation is hereby granted without fee, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation, and that references to the Association of Universities for Research in Astronomy Inc. (AURA), the National Optical Astronomy Observatories (NOAO), or the Image Reduction and Analysis Facility (IRAF) not be used in advertising or publicity pertaining to distribution of the software without specific, written prior permission from NOAO. NOAO makes no representations about the suitability of this software for any purpose. It is provided “as is” without express or implied warranty.
NOAO DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL NOAO BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
Copyright information of source code that is included in IRAF can be
found in the subdirectory
of the IRAF source code.
The last NOAO versions of IRAF had licensing problems with non-free code from the book Numerical Recipes and not acknowledging contributions from the IRAF64 project. These problems are described in detail here. They are all resolved in the community distribution of IRAF.