[icedchai]

The last "proprietary Unix" I worked with was AIX, way back in 2006. And that was only because their primary customer was an AIX shop. The code itself would actually run on Linux.

Previous to that (late 90's, early 2000's) it was mainly Solaris. One place was fairly heterogeneous, and had Solaris, HP-UX, Digital Unix (aka OSF/1, Tru64), and a couple others.

[anyfoo]

I think that last bit might have been somewhat common at the time. I had a small job as one of the unix-y guys at a software company dealing with a very similar collection of OSs. In their case, it was simply because the software they made ran on a lot of popular (and some not so popular) OSes, so the boxes running them (and, in most cases, building the software) had to be there.

[bstpierre]

As an intern in the mid 90s I babysat a similar mix. We also had some older SunOS boxes and some Irix, but mostly Solaris. I remember the HP as being the worst to work with of the bunch - for whatever reason if one of the tests was going to be broken it was on the HP.

[piyh]

We had AIX at my last job in 2021 and it was the least actively terrible part of our tech stack.

[nibbleshifter]

There is genuinely nothing wrong with a lot of the old stuff, in many cases its simply better than the latest and greatest React/Mongo/Whatever webshit stack that modern devs seem to emit.