A dog by what metric? In 1994 IRIX was the first 64 bit Unix kernel running on the first 64 bit workstation. In 1997, the same IRIX 6.5 could run on machines from 100Mhz/16MB to 512 cpus monsters. IRIX had really a nice, easy user interface, and many features (real-time IOs, /hw virtual filesystems giving a hint of /proc and /sys long before they came into existence, modular kernel, full 32 bits compatibility on 64 bits machines...) that were long to come on other OS.

Hah! RHEL 6 is only just getting GRIO. XFS is still a world-class filesystem. If you didn't love IRIX you weren't using it for what it was for.

IRIX was a god of an OS.

It had real time I/O. It had the best user interface at the time, with super fast scalable vector graphics for everything in '94. (Modern desktops have caught up some 13 years later). It had usable 64 bits everything before anyone else - R10000 was generally available in '95.

They were insanely fast compared to the Sun and Digital stations of the time - the only competitor was Digital Alpha, and IRIX beat Ultrix to the ground and mopped the floor with it.

These were the days of multiculture, where my employer insisted on having several Alphas, Suns, SGIs, RS/6000 and more to make sure we're not locked to any specific vendor.