Oh they tried NT. Even played with one of those machines. They even looked ugly. They do a lot of Linux now, and have been playing with hybrid architectures. Another bet of theirs that failed were their Altix systems since the Itanium went nowhere fast
I know they tried to add NT to their portfolio, but they kept using IRIX for their supercomputing systems, as well as for their higher-end workstations until they switched to Linux for the supercomputers, and completely gave up on workstations.
Today their systems almost all use Linux.
Obviously, they didn't switch to NT, they switched to Linux.
