The worst version of commercial
unix available. It's not as
nonstandard as
AIX, but it has plenty of deficiencies to make up for that. Often referred to as HP-SUX. HP-UX sounds great at first, with things like
kernel threads, but then you find out none of you current
programs will
port over to the damn thing without a lot of
work. Plus the
PA-RISC processor is a real
dog. And all of their cabinets look like they were designed in 1970.