Not very - there are several reference ones in various languages and frameworks. The difference I'm upset about is that Profile Manager got the closest to actin

Not very - there are several reference ones in various languages and frameworks. The difference I'm upset about is that Profile Manager got the closest to acting like a proper enterprise MDM, but still wouldn't let me supervise devices because I'm not a company. I'm not some weirdo who wants full control to devices I don't deserve it on, but I do want to make sure my grandparents' iPhones are up to date, or have the ability to make it beep when they call (from a land line) that they've lost it, or push family calendars or email accounts to their devices so they don't have to enter passwords. Apple has decided those features are only for the enterprise or schools, and I'm sadly neither. If you're interested this[0] is the MDM reference I'm most interested in these days. 0 - https://micromdm.io https://micromdm.io