The distribution reached end of life on January 14, 2014
Dear Fedora fans, we are very sorry to announced today, January 14, 2014, that the Fedora 18 (Spherical Cow) Linux operating system has reached end of life (EOL).Dubbed Spherical Cow, the Fedora 18 distribution was released exactly one year ago, on January 15, 2013. The system was powered by Linux kernel 3.11 and it featured the GNOME 3.6 desktop environment for the main edition, MATE, Cinnamon, KDE 4.9, Xfce 4.10, and improved storage management.
Today, January 14, the Fedora 18 operating system will no longer receive security and critical fixes or software updates, and no new packages will be added. Users are urged to upgrade to the latest stable version, Fedora 20, as soon as possible. Detailed upgrade instructions can be found at http://fedoraproject.org/wiki/DistributionUpgrades.