the first commercial loosely coupled clustering product was datapoint corporation's "attached resource computer" (arc) system, developed in 1977, and using arcnet as the cluster interface. clustering per se did not really take off until digital equipment corporation released their vaxcluster product in 1984 for the vax/vms operating system (now named as openvms). the arc and vaxcluster products not only supported parallel computing, but also shared file systems and peripheral devices. the idea was to provide the advantages of parallel processing, while maintaining data reliability and uniqueness. two other noteworthy early commercial clusters were the "tandem himalayan" (a circa 1994 high-availability product) and the "ibm s/390 parallel sysplex" (also circa 1994, primarily for business use).