Catamount (operating system)
The Cray XT3 supercomputer which uses Catamount on its compute nodes
Catamount is an operating system for supercomputers.[1]
Catamount is a lightweight kernel that provides basic functionality and aims for efficiency. The roots of Catamount go back to 1991 when SUNMOS was developed by Sandia National Laboratories and the University of New Mexico as a lightweight operating system. The Cray XT3 uses Catamount on compute nodes and Linux on server nodes.[1]