In June and November of each year the Top500 list of supercomputers is released. Each year, based on the list, the key operating system for supercomputing is Linux. Linux is cheaper to run and its excellent scalability features, along with its robust security and performance, make it an ideal choice for high performance computing (HPC) systems.
The recently released November Top500 list once again demonstrates that Linux dominates HPC – nearly 90 percent of the Top500 systems run on Linux. Three hundred and ninety-one of these systems are running an unspecified version of Linux. Sixty-two of the supercomputers are proven to run some version (including such variants as UNICOS/lc and CNL) of SUSE Linux Enterprise from Novell. Red Hat and its derivatives, including CentOS, comes in a distant second with 16 supercomputers.