"Now let's skip up to the top of the 2009 Linux
Sandwich, which is the open source operating system’s
dominance in supercomputing. In ultra high-end computing, where the
fastest and most powerful supercomputers are ranked on the list of
the Top500 Supercomputer Sites, Linux maintains more than 90% share
of the operating systems in use, with no other OS coming close. The
strength of Linux in this space, where it is used primarily in
clusters, is reinforced by an interconnect and application
ecosystem, contrary to where Linux has been historically in most
markets. We also see increased competition in HPC as Red Hat goes
after higher-end Unix replacement business, Novell looks to
maintain SUSE Linux strength, and Microsoft hopes to take advantage
of broader enterprise use of HPC with its Windows HPC Server
software."
