PowerPC Solaris on the RS/6000
One of the weirdest times in computing was during the mid-90s, when the major RISC vendors all had their own plans to dominate the consumer market and eventually wipe out Intel. This was a time that led to overpriced non-x86 systems that intended to wipe out the PC, Windows NT being ported to non-x86 platforms, PC style hardware paired with RISC CPUs, Apple putting the processor line from IBM servers into Macs, and Silicon Graphics designing a game console for Nintendo. While their attempts worked wonders in the embedded field for MIPS and the AIM alliance, quite a few of these attempts at breaking into the mainstream were total flops.
Despite this, there were some weird products released during this period that most only assumed existed in tech magazine ads and reviews. One such product was Solaris for PowerPC. Now Solaris has existed on Intel platforms for ages and the Illumos fork has some interesting ports including a DEC Alpha port, but a forgotten official port exists for the PowerPC CPU architecture. Unlike OS/2, it's complete and has a networking stack. It's also perhaps one of the weirdest OSes on the PowerPC platform.
I love machines from this era. There's some seriously weird hardware from that time floating around eBay for serious prices.