ExtremeXOS is the software or the network operating system used in newer Extreme Networks network switches.
[1] It is Extreme Networks second generation operating system after the VxWorks based ExtremeWare operating system.
ExtremeXOS is based on the Linux kernel and BusyBox.
[2] In July 2008 legal action was taken against Extreme Networks due to alleged violation of the GNU General Public License.
[3] Three months later the lawsuit was settled out of court.