Large, expensive, and very fast computers used either for number crunching or DataBase serving. The term implies approval, in contrast to Dinosaur.

Originally referring to supercomputers like the Crays, the term became more and more inclusive as processing power become more and more of a commodity. It first expanded to include MainFrames such as those built by IBM, and nowadays is sometimes also applied to very expensive x86 hardware -- usually large-scale SMP machines with large RAID arrays.