Cartes du Ciel is free software released under the terms of the
GNU General Public License
Copyright © 2006 Patrick Chevalley and the Skychart Documentation Team.
This work is licensed under the Creative Commons Attribution-Share Alike License.
To view a copy of this license, visit http://creativecommons.org/licenses/by-sa/3.0/
or send a letter to Creative Commons, 543 Howard Street, 5th Floor, San Francisco, California, 94105, USA.
To allow for its inclusion with the software distribution it is also licensed under the GNU Free Documentation License
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
To view a copy of this license, visit http://www.gnu.org/licenses/fdl.html