WebKit

WebKit
Name	WebKit
Developer	Apple Inc., KDE, Igalia, and others
Released	25 June 2001
Programming language	C++
Operating system	macOS, iOS, Linux, Microsoft Windows
Genre	Browser engine
License	LGPL 2.1 (parts), BSD-style
Website	https://webkit.org/

WebKit. It is a widely used browser engine that powers a significant portion of the modern web, most notably as the core of Safari and historically Google Chrome. The project originated from the KHTML and KJS libraries of the KDE project's Konqueror browser and has since evolved into a major open-source project primarily stewarded by Apple Inc.. Its development is a collaborative effort involving contributors from companies like Igalia and Samsung, and it supports a broad ecosystem of applications beyond traditional web browsers.

Overview

WebKit serves as the foundational rendering and scripting engine for displaying web content and executing JavaScript code. It is designed to be portable and embeddable, allowing it to be integrated into various applications across different operating systems. The engine implements key web standards as defined by the W3C and the Ecma International organization, ensuring compatibility with modern HTML, CSS, and ECMAScript specifications. Its architecture separates the high-level web-facing APIs from the lower-level platform-specific code, a design that facilitates its adoption in diverse software environments, from desktop applications to mobile devices and embedded systems.

History

The project began in 2001 when Apple Inc. engineers, led by Dave Hyatt, started modifying the KHTML engine from the KDE project for use in what would become Safari. Apple open-sourced the WebKit code in 2005, creating a collaborative project that attracted contributions from Nokia, Google, and Adobe Systems. A pivotal moment occurred in 2008 when Google Chrome launched using WebKit, significantly increasing its market share, though Google later forked it to create the Blink engine in 2013. Throughout its evolution, WebKit has been central to major platforms, becoming the mandatory engine for all third-party browsers on iOS and iPadOS per Apple's App Store policies.

Architecture

The architecture of WebKit is modular, primarily consisting of the WebCore rendering module and the JavaScriptCore engine. WebCore, written in C++, handles the parsing of HTML, layout with CSS, and rendering of DOM trees, while JavaScriptCore executes JavaScript code. This core engine interfaces with a "port" or abstraction layer that binds it to a specific platform's graphics, networking, and event systems, such as Cocoa on macOS or GTK on Linux. Other critical components include the WebKit API, which provides the interface for embedding the engine into applications, and the Web Inspector, a suite of debugging tools.

Features

WebKit is known for its early and robust implementation of modern web standards. It was a pioneer in supporting CSS Animations, CSS Transitions, and the HTML5 video element. The engine includes advanced features like the Accelerated Compositing system for smooth graphics performance, extensive support for WebGL and WebAssembly, and powerful developer tools accessible via the Web Inspector. It also places a strong emphasis on security and privacy, implementing features such as Intelligent Tracking Prevention to block cross-site tracking and robust sandboxing techniques to isolate web content.

Usage

Beyond Safari on Apple devices like the iPhone, iPad, and Mac, WebKit is the engine for the App Store browser on tvOS and the PlayStation 4 system software. It is embedded in numerous applications across various platforms, including the Linux-based GNOME Web browser (formerly Epiphany) and the BlackBerry 10 operating system. Its embeddable nature has made it a popular choice for displaying web content within native applications developed for Microsoft Windows and macOS, such as those built with Electron in its earlier versions.

Development

Development is managed openly through the WebKit.org website, with source code available via Git and contributions governed by a contributor license agreement. The project maintains a rigorous continuous integration system and a public bug tracker to manage changes and regressions. Major decisions are often discussed within the community and influenced by key stakeholders like Apple Inc. and Igalia. The engine's development roadmap is closely tied to the advancement of web standards within bodies like the W3C, with a focus on performance, security, and enabling new web APIs for application developers.

Category:Free software programmed in C++ Category:Web browsers Category:Apple Inc. software