[gobusto]

I used to work as a software developer in the UK insurance industry, and I can tell you that we (and hence several of the insurers/brokers we dealt with) used OpenVMS.

In contrast to some of the other comments here, we weren't using it because moving to another OS - or architecture - would have been a pain. In fact, our software originally ran on x86 machines at some point in the distant past, before we migrated it to OpenVMS relatively recently.

I don't know why OpenVMS was given preference over GNU/Linux, *BSD, or Windows; I'm guessing that the technical managers above me had their reasons, but I couldn't say what they were.

I left that job a few years ago, but I think that they did intend to eventually phase out the VMS systems as our new, GUI-based product slowly replaced the older text-based one.