[OJFord]

Windows would be a deal-breaker for me I think, ideally I like to use Linux but could (and have) get by with macOS.

I also think non-git would be, it's just too ingrained. Maybe one of the few more recent interesting looking potential successors (I just can't remember names, sorry) posted here every so often, but not mercurial or whatever.

Version control's in a special place in that you have to use the same as each other, but like OS I think being particularly prescriptive about anything would massively put me off. I want both to use vim as I have since university today, but also the freedom to decide actually I want to switch to VSCode or Helix or whatever - not have to use Jetbrains because that's what we do here, nor have to get special dispensation for my choice and then be (or feel that I am) tied to it.

I'm sure some answers are going to be 'they're just tools, who cares' but IMO yes exactly, they're my tools that I'm using to do a job for you, you care about the output, why do you care about the tools.

(Macs muddy the water a bit by tying provided hardware somewhat to the OS. You can't give everyone ThinkPads and also be fine with people using MacOS, you've inherently said it's either Windows or Linux. I don't know what the state of native Windows on Arm Macs is, but I don't think Asahi Linux is ready for daily driving on work machines yet (i.e. where you don't want to be saying 'err well I did something a little different to my laptop and err I have a bit of a driver problem' when you can't make any progress on something.).)