7-Zip Copyright (C) 1999-2010 Igor Pavlov.
Licenses for files are:
1) 7z.dll: GNU LGPL + unRAR restriction
2) All other files: GNU LGPL
The GNU LGPL + unRAR restriction means that you must follow both GNU LGPL rules and unRAR restriction rules.
Note:
You can use 7-Zip on any computer, including a computer in a commercial organization. You don't need to register or pay for 7-Zip.
GNU LGPL information
This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
You can receive a copy of the GNU Lesser General Public License from http://www.gnu.org
unRAR restriction
The decompression engine for RAR archives was developed using source code of unRAR program.
All copyrights to original unRAR code are owned by Alexander Roshal.
The license for original unRAR code has the following restriction:
The unRAR sources cannot be used to re-create the RAR compression algorithm, which is proprietary. Distribution of modified unRAR sources in separate form or as a part of other software is permitted, provided that it is clearly stated in the documentation and source comments that the code may not be used to develop a RAR (WinRAR) compatible archiver.
Igor Pavlov