Although it also names a couple of hardware companies, S3's main referent is computing is to the "Simple Storage Service" [L1 ] among Amazon Web Services [L2 ]. Darren New has been working on a Tcl interface [L3 ].
S3 is also the name of an Algol 68 based system programming language used on ICL VME (Virtual Machine Environment) mainframes [L4 ].