So, Gatekeeper applies to basically any piece of software that a user would obtain, since the internet is really the way people get software these days (as evid

So, Gatekeeper applies to basically any piece of software that a user would obtain, since the internet is really the way people get software these days (as evidenced by Apple eliminating optical drives from Macbooks). Sure, it's security. So is Apple's restriction on not allowing 3rd party browsers on iOS. At least according to Apple. - unless they use the hobbled Mobile Safari engine without JIT.