Just curious, why the author thinks that Safari is a joke?
We can't even debug mobile Safari pages without a Mac. So it ends up as 'probably works' because it works in Chrome.
There used to be Windows version of Safari, but it is not updated anymore.
Safari is based on Webkit/KTHML/Konqueror source code, some of the source code is public and has been contributed back from Apple to Webkit. But full source code of Safari is not public.