The Scalable System Software department has pioneered the research, development, and use of lightweight kernel operating systems for large-scale high-performance computing systems. Sandia is the only DOE national laboratory to deploy its own operating system software on large-scale vendor-supplied production systems. Sandia, together with researchers at the University of New Mexico, partnered with Intel in the 1990's to deploy the SUNMOS lightweight kernel on the Intel Paragon and the Puma lightweight kernel on the ASCI Red machine, which was the first terascale parallel computing system. More recently, Sandia partnered with Cray to develop and deploy the Catamount lightweight kernel on Sandia's Red Storm machine, which was the prototype for Cray's most commercially successful line of supercomputers - the Cray XT. The multi-core version of Catamount was also awarded the prestigious R&D100 Award in 2009.