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Last modified: 6 August 2025

URL: https://cxc.cfa.harvard.edu/ciao/download/license.html

Licenses

License

The CIAO software distribution contains software developed by the
Chandra X-Ray Center (Smithsonian Astrophysical Observatory and
contracted affiliates) and "off-the-shelf" software developed by 
various third parties.

The CIAO software distribution is licensed for use under 
the GNU General Public License (GPL) Version 3 (or at your option
any later version). The terms of the GNU General Public License
are described in the COPYING file in the root directory of the 
$ASCDS_INSTALL tree.

Software developed solely by the Smithsonian Astrophysical
Observatory is copyright the Smithsonian Astrophysical Observatory 
and is in addition licensed for use as described in the LICENSE.SAO 
file in the root directory of the $ASCDS_INSTALL tree.

GPLv3 copyleft.


Copyright

/***********************************************************************/
/*     Copyrights:                                                     */
/*                                                                     */
/*     Copyright (c) 1999 2023 Smithsonian Astrophysical Observatory   */
/*                                                                     */
/*    Permission to use, copy, modify, distribute,  and  sell  this    */
/*    software  and  its  documentation  for  any purpose 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  docu-    */
/*    mentation,  and  that  the  name  of  the  Smithsonian Astro-    */
/*    physical Observatory not be used in advertising or  publicity    */
/*    pertaining  to distribution of the software without specific,    */
/*    written  prior  permission.   The  Smithsonian  Astrophysical    */
/*    Observatory  makes  no  representations about the suitability    */
/*    of this software for any purpose.  It  is  provided  "as  is"    */
/*    without express or implied warranty.                             */
/*    THE  SMITHSONIAN  ASTROPHYSICAL  OBSERVATORY  DISCLAIMS   ALL    */
/*    WARRANTIES  WITH  REGARD  TO  THIS  SOFTWARE,  INCLUDING  ALL    */
/*    IMPLIED  WARRANTIES  OF  MERCHANTABILITY  AND FITNESS, IN  NO    */
/*    EVENT  SHALL  THE  SMITHSONIAN  ASTROPHYSICAL  OBSERVATORY 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.                         */
/*                                                                     */
/***********************************************************************/