Question: What descendant of KTHML was developed by Apple?

full_context: Document 1: KHTML: KHTML is a HTML layout engine developed by the KDE project. It is the engine used by the Konqueror web browser. Descendants of KHTML are used by some of the world's most widely used browsers, among them Google Chrome, Safari and Opera. Distributed under the terms of the GNU Lesser General Public License, KHTML is free software.
Document 2: System Information (Mac): System Information (previously known as System Profiler) is a software utility derived from field service diagnostics produced by Apple's Service Diagnostic Engineering team, at that time located in Apple satellite buildings in Campbell, California, that was bundled with the classic Mac OS since Mac OS 7.6 under the name Apple System Profiler. In Mac OS X v10.0, the first release of macOS, it was renamed System Profiler; with the release of Mac OS X 10.7 "Lion" it was again was renamed to System Information. Other new features in Lion are the ability to look up support information for the user's hardware model as well. In OS X Mountain Lion and later versions of macOS users can also access System Information by holding down the option key and "System Information..." will replace "About This Mac" in the Apple Menu.
Document 3: Qutebrowser: qutebrowser is a web browser for Linux, Windows, and macOS operating systems with vim-style key bindings and a minimal GUI. It is keyboard-driven and is inspired by similar software such as Vimperator and dwb. It uses DuckDuckGo as the default search engine. Qutebrowser is included in the native repositories of Linux distributions such as Fedora and Arch Linux.
Document 4: Safari (web browser): Safari is a web browser developed by Apple based on the WebKit engine. First released in 2003 with Mac OS X Panther, a mobile version has been included in iOS devices since the introduction of the iPhone in 2007. It is the default browser on Apple devices. A Windows version, now discontinued, was available from 2007 to 2012.
Document 5: Browser extension: A browser extension is a plug-in that extends the functionality of a web browser. Some extensions are authored using web technologies such as HTML, JavaScript, and CSS. Others are developed using machine code and application programming interfaces (APIs) provided by web browsers, such as NPAPI and PPAPI. Browser extensions can change the user interface of the web browser without directly affecting viewable content of a web page; for example, by adding a browser toolbar.
Document 6: ISync: iSync is a software application first released by Apple Inc. on Jan 2, 2003. Apple licensed the core technology from fusionOne. It ran only under Mac OS X and was used to synchronize contact and calendar data from Address Book and iCal with many non-Apple SyncML-enabled mobile phones via a Bluetooth or USB connection. Support for many (pre-October 2007) devices was built-in, with newer devices being supported via manufacturer and third-party iSync Plugins. Support for Palm OS organizers and compatible smartphones was removed with the release of iSync 3.1 and Mac OS X 10.6 Snow Leopard. BlackBerry OS, Palm OS, and Windows Mobile (Pocket PC) devices could not be used with iSync, but were supported by third-party applications. Before the release of Mac OS X 10.4, iSync also synchronized a user's Safari bookmarks with the, then .Mac subscription service provided by Apple.
Document 7: Internet Explorer 3: Microsoft Internet Explorer 3 (IE3) is an unsupported graphical web browser released on August 13, 1996 by Microsoft for Microsoft Windows and on January 8, 1997 for Apple Mac OS (see IE for Mac). It began serious competition against Netscape Navigator in the first Browser war. It was Microsoft's first browser release with a major internal development component. It was the first more widely used version of Internet Explorer, although it did not surpass Netscape or become the browser with the most market share. During its tenure, IE market share went from roughly 3–9% in early 1996 to 20–30% by the end of 1997. In September 1997 it was superseded by Microsoft Internet Explorer 4.
Document 8: Yandex Browser: Yandex Browser is a freeware web browser developed by the Russian web search corporation Yandex that uses the Blink web browser engine and is based on the Chromium open source project. The browser checks webpage security with the Yandex security system and checks downloaded files with Kaspersky anti-virus. The browser also uses Opera Software's Turbo technology to speed web browsing on slow connections.
Document 9: IOS: iOS (formerly iPhone OS) is a mobile operating system created and developed by Apple Inc. exclusively for its hardware. It is the operating system that presently powers many of the company's mobile devices, including the iPhone, iPad, and iPod Touch. It is the second most popular mobile operating system globally after Android.
Document 10: Origyn Web Browser: Origyn Web Browser (OWB) is a discontinued web browser that was synchronized with WebKit and sponsored by the technology company Pleyo. OWB provides a meta-port to an abstract platform with the aim of making porting to embedded or lightweight systems faster and easier. This port is used for embedded devices such as set-top boxes, and other consumer electronics.
Document 11: Apple Inc.: Apple Inc. is an American multinational technology company headquartered in Cupertino, California that designs, develops, and sells consumer electronics, computer software, and online services. The company's hardware products include the iPhone smartphone, the iPad tablet computer, the Mac personal computer, the iPod portable media player, the Apple Watch smartwatch, the Apple TV digital media player, and the HomePod smart speaker. Apple's consumer software includes the macOS and iOS operating systems, the iTunes media player, the Safari web browser, and the iLife and iWork creativity and productivity suites. Its online services include the iTunes Store, the iOS App Store and Mac App Store, Apple Music, and iCloud.
Document 12: NPAPI: Netscape Plugin Application Programming Interface (NPAPI) is an application programming interface (API) that allows plugins (more specifically, browser extensions) to be developed for web browsers. It was first developed for Netscape browsers, starting in 1995 with Netscape Navigator 2.0, but was subsequently adopted by other browsers.
Document 13: UltraBrowser: UltraBrowser is a graphical web browser developed by UltraBrowser.com Inc, based upon the Trident layout engine, part of Internet Explorer since IE version 4. The program is lightweight and features an advanced GUI which features various links, channels and search facilities. The latest version was released on May 19, 2005. Aside from their self-branded browser, the company also specialises in custom-branded browsers for companies and organisations. One of their most notable clients was Tiscali SpA, in which the two companies signed a contract to produce a Tiscali-branded browser which later became known as Tiscali 10.0, released in 2002.
Document 14: MacOS: macOS (pronounced ; previously Mac OS X and later OS X) is the current series of Unix-based graphical operating systems developed and marketed by Apple Inc. designed to run on Apple's Macintosh computers ("Macs"). It has been preinstalled on all Macs since 2002. Within the market of desktop, laptop and home computers, and by web usage, it is the second most widely used desktop OS after Microsoft Windows.
Document 15: GNU LibreJS: GNU LibreJS, or simply LibreJS, is a free software web browser extension for Mozilla Firefox-based browsers, created by the GNU Project. Its purpose is to block nonfree nontrivial JavaScript programs and allow free or trivial JS in a user's web browser. The add-on was created to address the so-called "JavaScript Trap" described by Richard Stallman, a situation in which many users unknowingly run proprietary software in their web browsers.
ground_truth: Safari