KHTML

KHTML. KHTML is a web browser engine and layout engine originally developed by the KDE project for use in its Konqueror file and web browser. It is an open-source engine written in C++ and licensed under the LGPL, known for its standards compliance and modular design. The engine's architecture and codebase were famously forked to create WebKit, which later became the foundation for major browsers like Apple Safari and Google Chrome.

History

The development of KHTML began in 1998 as part of the KDE project's effort to build an integrated file manager and web browser, Konqueror. It was created as an alternative to proprietary engines and was designed to adhere closely to W3C standards. A significant milestone occurred in 2001 when engineers at Apple Inc. selected the codebase as the foundation for their new WebKit engine, citing its clean design and standards compliance. This fork led to substantial investment and development from Apple, which eventually outpaced the original KDE development efforts. The last major release from the KDE team was integrated into KDE 4, though active maintenance by the original developers has since diminished.

Architecture

KHTML is built on a modular, object-oriented architecture using C++. Its core components include the DOM and CSS rendering modules, a JavaScript interpreter originally based on KJS, and a network abstraction layer. The engine separates parsing, rendering, and scripting into distinct libraries, promoting code reuse and easier maintenance. This design influenced subsequent engines, most notably the structure of WebKit. The KDE libraries, such as KIO for network access and Qt for its graphical toolkit, were integral to its integration within the KDE desktop environment.

Features

The engine was notable for its early and robust support for web standards, including HTML 4.01, CSS2, and DOM Level 1 and 2. It implemented partial CSS3 and HTML5 features during its active development. KHTML also featured a fast and compact JavaScript engine, KJS, which contributed to the development of WebKit's JavaScriptCore. Other advanced features included support for SSL, incremental rendering, and a plugin interface for handling additional content types like Java applets and Flash.

Usage and derivatives

KHTML's primary application was within the Konqueror browser, part of the KDE desktop environment on Unix-like operating systems. Its most significant derivative is undoubtedly WebKit, created by Apple Inc. for Safari. The WebKit fork itself later spawned Blink, the engine used by Google Chrome, Microsoft Edge, and Opera. Other projects, such as the Android browser and GNOME's early Web browser, also utilized branches of the codebase. While Konqueror still supports KHTML, most derivatives have long since transitioned to using WebKit or Blink.

See also

* WebKit * Blink (browser engine) * Gecko (software) * Trident (software) * Konqueror * KJS * KDE

Category:Web browser engines Category:KDE Category:Free software programmed in C++ Category:1998 software