http://www.gnu.org/graphics/fsf-bk.jpg
FSF is the principal organizational sponsor of the GnU Project.
The Free Software Foundation (FSF), founded in 1985, is dedicated to promoting computer users' right to use, study, copy, modify, and redistribute computer programs. The FSF promotes the development and use of free (as in freedom) software ---particularly the GNU operating system(used widely today in its GNU/Linux variant)--- and free (as in freedom) documentation. The FSF also helps to spread awareness of the ethical and political issues of freedom in the use of software.
http://www.gnu.org/fsf/fsf.html
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