The NYC subway system runs on OS/2
This got me wondering...if you were building out a system like this today, which OS would you choose that wouldn't seem ridiculous 30 year later? And why aren't we building OSes that are simple and feature-poor with the intention that they'll be used for 30 years? Or the airline problem: it must be annoying that the tech you put in seatbacks has a short shelf life and will look primitive compared to the phones in everyone's pockets.