The Free Software Foundation (FSF) is a not-for-profit organization founded by RichardStallman to promote FreeSoftware. Its main objective is the release of a completely free replacement for Unix, called GNU. GNU stands for “GNU’s Not Unix.”
The FSF’s website can be found at http://www.fsf.org/. The GNU website can be found at http://www.gnu.org. GnuEmacs can be found on the GNU website.
GNU/Linux is an operating system combining the GNU System with the Linux kernel.