The IBM RS/6000 was a range of RISC based Unix servers, workstations and even supercomputers. One of the best known uses of them was perhaps the Deep Blue chess computer that was build using a RS/6000 supercomputer with custom chess accelerator chips inside. Sadly I don't have one of those giant machines, but a much more managable workstation.
Specification wise, this was still a fast machine. A 400Mhz POWER3 CPU, 2GB RAM and an IBM GXT6000P GPU was pretty insane back in 2000. At launch it was called the fastest workstation! On the software side of things, it runs AIX. And that's about it. Like a good old Unix workstation you had CDE as desktop environment. Lovely!
This machine is still kind of usable, there are plenty of open source programs available, though I sadly haven't found something like CATIA or some other workstation software for this yet. All in all a fun odd and surprisingly usable machine! And it looks real pretty inside as well:
