Most is a LONG way from all, though, isn't it?
You need to know the structure of what can be called Safari. On Macs there are APIs for core web technologies. If you want web rendering in your app, you just leverage these APIs.
I've developed more than my share of software, thank you very much. And I know about using pre-installed APIs. However, there are often good reasons to roll your own, including extending functionality beyond what is possible with the stock APIs, supporting new and upcoming standards, and sometimes doing it just because you have a different idea and think you can do it better and faster.
Microsoft has essentially the same thing with IE on Windows.
BS, and if you knew about that development and "API" leverage you talked about you'd know you're spouting BS. Microsoft's browser has a COMPLETELY DIFFERENT rendering engine than Chrome or Firefox (number 3 and number 2, respectively, in computer browser share). They share NONE of the same code, and the ONLY API calls used by those engines are what are used to paint on the screen. They each render the HTML with WebKit, as opposed to MSFT's Trident engine.
Can you install and use Trident on an iPhone? That's the point, and one that shows there's a big difference here.
Apple has solid technical reasons for not allowing a browser free-for-all. It's not about some evil plan.
Yes, it's called lock-in and cash-flow. Profit is not evil; pretending to be altruistic and caring and refusing to allow you to do with your system what you want is, IMHO.
4 out of 5 dentists can.