Visited Internet Archive, saw a server (are there any real data centers that offer tours? If you know of any let me know)
Before I was a software engineer I toured a solo theatre show, and my sound queues lived on a mac-only QLab file. I toured with that file on a thumb drive, and for the first five or six theaters I just handed it off to the booth technician and everything worked. But in the back of mind I kinda knew someday I'd be in a theatre that didn't have a Mac, and I'd be totally out of luck. Ottawa was that theatre.
Confusing matters more-so, I actually had a mac laptop with me on the road that I used for admin, but it was too old to run QLab3.x. I jokingly (but also not totally jokingly) said to my Ottawa theatre contact, "Yeah, guess you couldn't take one of those iMacs in the ticket booth and put it in the light booth for my show, huh?" and he shook his head no.
What with "The show must go on" and all (an over-used cliche, IMO btw. Sometimes there's good reasons to cancel a show!) I was basically resigned to buying a new laptop when I found a forum post suggested that you could still get QLab2.x through the internet archive.
It was a magical software moment. It just worked. I'm still surprised and not sure I'm remembering everything right because I didn't think the Internet Archive kept, like, the software you can download and maybe they don't usually but this just worked.
I rebuilt my queues in the older but equivalent UI, performed for dozens of very nice Canadians, and the sound queues were great.
If you've found this blog in your own search for a copy of QLab2.3.9 1: break a leg and 2: here you go...
https://web.archive.org/web/20160808060136/http://figure53.com/qlab/download/archive
Won't run on my M4 but I think that's still the software.