PRISM (Parallel Reduced Instruction Set Multiprocessor) was Apollo Computer's high-performance CPU used in their DN10000 series workstations.
For instance, for a CPU with two functional units, like the PRISM, the compiler would find pairs of safe instructions and stuff them into a single larger word.
Note that PRISM was a multi-chip CPU board, not a single microprocessor; this was fairly common for high-end CPUs at the time.
Nevertheless, several features of the PRISM design were put into later generations of the HP-PA architecture, and the two main proponents of the VLIW concept, Intel and HP, later collaborated on the Itanium.
[citation needed] Although the Intel i860 also used a VLIW (or properly LIW in both cases, as two is not "very" long), extracting performance from the i860 proved notoriously difficult, and in practice the PRISM was much faster.
Digital Equipment Corporation also engineered a RISC chip named PRISM during the same era, but that project was canceled in 1988, and never entered production.