7-Zip is open source software. Most of the source code is under the GNU LGPL license. The unRAR code is under a mixed license: GNU LGPL + unRAR restrictions. Check license information here: 7-Zip license.
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
Fuente : http://www.7-zip.org/
