[pavlov]

I believe Apollo had a proprietary OS with limited Unix compatibility. So maybe the grandparent poster is right about the Model 16 being the only other non-Sun desktop Unix for a while, as long as you define Unix tightly enough.

[kjellsbells]

Sun gets the crown because prior to the sun/1 there wasnt really any such thing as a UNIX workstation. You had a terminal connected into a host running UNIX (or VMS) and that was that. My pet theory is that Sun succeeded against Apollo because Sun decided to sell to Wall St quants for their day job number crunching whereas Apollo (and later HPE) sold to engineers doing simulations and CAD. Naturally the quants told their colleagues and the stock went brrr.

Later entrants like SGI targeted their workstations at media creatives (helpfully, Apple were in crisis by this time so A/UX wasnt remotely a problem). IBM and DEC just produced me-too workstations but there was nothing special about AIX or Ultrix unless you were already a customer.

The UNIX wars of the 90s were basically the UNIX vendors trying to take over the whole market and not just their classic turf.