Yeah, I’ve seen a lot of it for two things.

First being sqlserver, though that’s been able to run on linux for a long time now, there’s a bunch of features not supported but not a deal breaker for a lot of people, I haven’t encountered ssis or ssas in years for example.

Second being Internet Information Services (IIS), which some people really seem to like.

Wouldn’t be surprised if active directory required a windows machine either, definitely a bunch of cases I’m not considering or aware of but I’m no sysadmin.

I haven’t looked at Nix in detail but you got me interested for 3d printers in particular, already have my klipper config in git if an SD card fails on me, going to have to look at doing that for the os too.