> or like one of Apple's arch-competitors is using Apple's open source code to compete with them
WebKit is based on KHTML though from KDE, so not entirely Apple's. Not to mention that chrome uses V8 which is not JScore from Apple but full Google's code.
I don't mean to discredit Apple's contributions, but your comments seem to suggest to me that WebKit remains open source for benevolent reasons.
They built the project on KHTML so they wouldn't have to start from scratch. And because KHTML is under the LGPL, WebKit will have to remain open source unless they removed all KHTML-related code, which I'm sure is not worth the investment.
WebKit is based on KHTML though from KDE, so not entirely Apple's. Not to mention that chrome uses V8 which is not JScore from Apple but full Google's code.