They were a major phone switch manufacturer (long since absorbed by someone else). Their original design was, IIRC, a Z8000. As those parts were EOLed they shifted to the 68K and wrote a Z8000 emulator for the 68K. They later shifted to the PPC and ported their Z8K emulator to the PPC. We supplied a frozen version of the GCC PPC cross compiler. They had their own frozen version of a Z8K toolchain I think.

Their SLA was something like "less than five minutes of downtime per decade" -- no rebooting, realtime performance, no other interruption -- and they believed their extreme conservatism helped them get there.