The Free Software Foundation (FSF), established in 1985, is dedicated to promoting computer users’ rights to use, study, copy, modify, and redistribute computer programs. In this case, the concept of free software is a matter of liberty not price. Think of “free” as in “free speech.” The FSF promotes the development and use of free software, particularly the GNU operating system, used widely in its GNU/Linux variant.
The commencement of the GNU project in 1984, with its goal to give users freedom, required the establishment of new distribution terms that would prevent the project being turned into proprietary software. The method used was Copyleft and the resulting license was called the GNU General Public License (GNU GPL). Today the GNU GPL is the most widely used Free Software license, and as its author, the FSF works to help the wider community use and comprehend it.