'''KJS''' is [[KDE]]'s [[ECMAScript]]/[[JavaScript engine]] that was originally developed for the [[KDE]] project's [[Konqueror]] web browser by [[Harri Porten]] in [[2000]].
On June 13, 2002, [[Maciej Stachowiak]] announced on a mailing list that [[Apple Inc.|Apple]] was releasing [[WebKit#JavaScriptCore|JavaScriptCore]], a framework for [[Mac OS X]] that was based on KJS<ref>[http://web.archive.org/web/20070310215550/www.opendarwin.org/pipermail/kde-darwin/2002-June/000034.html kde-darwin mailing list, June 2002]</ref>. Through the WebKit project, JavaScriptCore has since evolved into SquirrelFish Extreme, a JavaScript engine that compiles JavaScript into native machine code.