ANONYMOUS Anyone who doesn't know that Safari is based on an opensource browser is just not paying attention.
But, building on an existing opensource browser base, Apple created a browser arguably better than all the opensource browsers currently available and did it in, comparably speaking, no time flat. Sure, yes, of course, we know that Apple did not start from scratch. Others could have conceivably done the same in building on something that already exists. But it has not happened, no one has gotten as far as Safari has in such a short time. I have used every browser there is for OS X, and not just in passing. I have given them all a respectable workout. Nothing beats Safari for speed and looks (looks: both in the way of GUI and in the way of rendering pages) in my experience and on my Macs.
No opensource group has the resources with which to crack the whip such as Apple has. And Microslop? They are not even on my radar. I wouldn't use any of their software under any circumstances. Final thought: if your sense of aesthetics tells you that there is a better-looking and better-rendering browser out there, you would not know the difference between Budweiser and Sierra Nevada Pale Ale.
(Version 0.8.3)