Crays are cool - the last bastion of "money is no object" computing. Purveyor to Nuclear Weapons Designers, Meteorologists, Spooks, and Computer Graphics people (who have an insatiable appetite for computing cycles).
Apple Computer bought a Cray X/MP-48 (four 9ns clock cycle processors, eight megawords of RAM) to help design a supercomputer on a chip. The project, alas, failed.
A probably apocryphal story: John Scully met Seymour Cray, and told Seymour, "You know, we're using a Cray to design the next Macintosh." Seymour scratched his head and thoughtfully replied, "Well, that's funny - I'm using a Macintosh to design the next Cray."
Apple's Cray subsequently found a useful life doing plastic flow modelling for the injection molds that Apple used for the cases of its products (the Cray cut months off the time to produce a production-quality plastic mold tool, and saved hundreds of thousands of dollars a shot). It was also a symbol of Apple Computer's commitment to having a world-class R&D facility, which served to attract many superior computing researchers over the years.
They've all been laid off now, of course.
I inherited this beast from the Design Simulation team at Apple. UNIX is perfect for multiprocessor machines - it wants to spawn processes like fish lay eggs, and so it's easy to use the full capabilities of such a machine. Now, if IRIX (SGI's version of UNIX) didn't suck so bad (they did some clever things, but it's still System V down to its core, and that core shows).
[Apple] [Cray] [DEC] [Sun] [SGI]