Good article about Google forking Webkit under the name Blink by John Siracusa:
When Apple decided to make its own web browser back in 2001, it chose KHTML/KJS from the KDE project as the basis of its rendering engine. Apple didn’t merely “adopt” this technology; it took the source code and ran with it, hiring a bunch of smart, experienced developers and giving them the time and resources they needed to massively improve KHTML/KJS over the course of several years. Thus, WebKit was born.
Even has some cool-looking graphs.