It's a little sad to see the article start with "Apple-developed web rendering engine..."
The reason even the most up to date Chrome and Safari browsers still have KHTML in their user-agent header is because of the KDE heritage.
Were it not for The Kalle Dalheimer Experience project (KDE for the uninitiated) and their bold move to go and build a HTML rendering engine the right way rather than trying to shoe-horn the Mozilla hodgepodge into a working browser application, there wouldn't have been a Konqueror browser with a KHTML rendering engine that was so good that when Apple wanted to build a browser they actually chose it as their base and said "we can build on this".
So yeah, Apple invested massively in this. But they did not start it, and had it not been for the KDE project and the amazing Konqueror initiative, Apple might well have chosen to build on Mozilla and who knows what Google might have done (instead of building on webkit) for Chrome... The world surely would have been a darker place and my point is I just think KDE should get a bit of credit for that.