1. Any hardware requiring raised flooring and special power. Used especially of old minicomputers and mainframes, in contrast with newer microprocessor-based machines.
In a famous quote from the 1988 Unix EXPO, Bill Joy compared the liquid-cooled mainframe in the massive IBM display with a grazing dinosaur "with a truck outside pumping its bodily fluids through it". IBM was not amused.
Compare big iron; see also dinosaurs mating.
2. [IBM] A very conservative user; a zipperhead.