http://k.blog.com/2795885/Microsoft has long been known for giving an unfair edge to its products by using secret operating system APIs. The most known cases are the ones involving the networking code, allowing IIS to beat Netscape Server (back in the day), as well as MS Office's widget APIs, which were indeed developed by the office team but took forever to be integrated in the main OS widget library.
What is a lesser known fact is that Apple plays the exact same game. The firefox dev team, specifically Vladimir Vukićević (with that name, he should be playing football), have uncovered a hundred or so secret OS entry points by looking at the webkit headers.
The story, in short, is that OSX by default limits the rendering speed to 60fps, which adversely affected Firefox when a page is smooth scrolled. Apple's supported workaround to this limitation is disabling coalesced screen updates to the whole application. However, Safari does not do that and is not limited to 60fps. The reason? A secret API call to programatically disable coalesced updates. After identifying this call, a slew of others became apparent in this header file.
Choosing between Gates and Jobs is like picking the shade of red in closed software hell.