Enter Apple

In 2001, Apple adopted the KHTML engine and the KDE JavaScript Engine
(KDE) to use as the base for its Safari web browser. Apple called its Mac OS
version of these two engines WebCore and JavaScriptCore. The combination
of WebCore and JavaScriptCore, along with the Apple-specific code written to
tie everything together, became known as WebKit.
From the time that Apple first announced WebCore and JavaScriptCore, they
were open source. It wasn’t until 2005, however, that Apple released the
entire WebKit project as open source.

Konqueror

was the first

browser

based on

the KHTML

engine.

WebKit basically started as a way for Apple to save time in creating its own
web browser. The choice to use KHTML, rather than another browser engine,
was made for three reasons: KHTML was small (in terms of lines of code), the
code was clean and well-written, and the browser was standards-compliant.
In short, KHTML was the best available foundation for building the next-generation
browser engine now known as WebKit.