They basically reinvented mainframes. Seems it has a lot in common with Z series.
Scalable locked in hardware, virtualization, reliability, engineered for hardware swaps, upgrades.
A proprietary operating system (?) from what someone said. (Offshoot of Solaris +++ (???) By that I mean that most of it, or all of it might be open sourced forks, but it will be an OS only meant to run on their systems.
(It would be fun to get it working at home, on a couple of PCs or a bunch of PIs)
They lack specialized processors to offload some workloads to.
Perhaps in modern terms shelfs of GPUs or a shelf fast FPGA , DSP processors. The possibilities are huge.
I didn't find any mention of from what I read.
They also lack the gigantic legacy effort to be compatible, which is a good thing.