named Catamount, which is based on the operating system of ASCI Red called "Cougar". A userspace implementation of the Lustre file system, named liblustre, was ported to the Catamount environment using the libsysio library to provide POSIX-like semantics. This filesystem client ran in the single-threaded Catamount environment without interrupts, and only serviced IO requests when explicitly allowed by the application, to reduce jitter introduced by background file system operations. Red Storm was decommissioned in 2012. References Cray products Parallel computing X86 supercomputers United States Department of Energy