AMD had their own non-x86 instruction set once upon a time. I remember using it in the mid-90s in some embedded thing it worked, but as a developer once there is a compiler all instruction sets are hidden so I can't comment.
The article says it got designed in to a bunch of laser printers, but not which ones.
There were a bunch of RISC designs floating around then. The ones still relatively familiar are those that were being used as workstation CPUs -- SPARC, MIPS, POWER/PowerPC, DEC Alpha. But there were also the 29k, the Motorola 88000, and Intel i860. Probably others I'm not remembering.