GNU (GNU's Not Unix)

"GNU" is a recursive acronym for "GNU's not Unix". The acronym is used to refer to a number of projects developed by the Free Software Foundation (FSF):


 * GNU operating system: A Unix-like operating system for computers. GNU is the operating system used by Linux. See http://www.gnu.org/gnu/linux-and-gnu.html.
 * GNU licence/copyright: A series of licences designed for ensuring the non-restrictive distribution of software and documentation. See GNU Public Licence (GPL) and Free Documentation Licence (FDL).

"Free" in GNU-speak does not necessarily mean "gratis". GNU-based and/or licenced software can be sold. Rather it means "open". GNU software and documentation can be modified, redistributed, sold, or given away on condition that subsequent users receive the same right to modify, repackage, redistribute, sell, or give the software away as well.

Additional information

 * Information on GNU (and similar) licences: http://www.gnu.org/licenses/licenses.html
 * Information on the GNU operating system: http://www.gnu.org/