Browser engine in the context of Web browser

A table is an arrangement of information or data, typically in rows and columns, or possibly in a more complex structure. Tables are widely used in communication, research, and data analysis. Tables appear in print media, handwritten notes, computer software, architectural ornamentation, traffic signs, and many other places. The precise conventions and terminology for describing tables vary depending on the context. Further, tables differ significantly in variety, structure, flexibility, notation, representation and use. Information or data conveyed in table form is said to be in tabular format (adjective). In books and technical articles, tables are typically presented apart from the main text in numbered and captioned floating blocks.

Google Chrome is a cross-platform web browser developed by Google. It was first released in 2008 for Microsoft Windows, built with free software components from Apple WebKit and Mozilla Firefox. Versions were later released for Linux, macOS, iOS, iPadOS, and also for Android, where it is the default browser. The browser is also the main component of ChromeOS, on which it serves as the platform for web applications.

Most of Chrome's source code comes from Google's free and open-source software project known as Chromium, but Chrome is licensed as proprietary freeware. WebKit was the original rendering engine, but Google eventually forked it to create the Blink engine; all Chrome variants except iOS used Blink as of 2017.

Mozilla Firefox, or simply Firefox, is a free and open-source web browser developed by the Mozilla Foundation and its subsidiary, the Mozilla Corporation. It uses the Gecko rendering engine to display web pages, which implements current and anticipated web standards. Firefox is available for Windows 10 or later versions of Windows, macOS, and Linux. Its unofficial ports are available for various Unix and Unix-like operating systems, including FreeBSD, OpenBSD, NetBSD, and other operating systems, such as ReactOS. It is the default, pre-installed browser on Debian, Ubuntu, and other Linux distros. Firefox is also available for Android and iOS. However, as with all other iOS web browsers, the iOS version uses the WebKit layout engine instead of Gecko due to platform requirements. An optimized version was also available on the Amazon Fire TV as one of the two main browsers available with Amazon's Silk Browser, until April 30, 2021, when Firefox would be discontinued on that platform. Firefox is the spiritual successor of Netscape Navigator, as the Mozilla community was created by Netscape in 1998, before its acquisition by AOL. Firefox was created in 2002 under the codename "Phoenix" by members of the Mozilla community who desired a standalone browser rather than the Mozilla Application Suite bundle. During its beta phase, it proved to be popular with its testers and was praised for its speed, security, and add-ons compared to Microsoft's then-dominant Internet Explorer 6. It was released on November 9, 2004, and challenged Internet Explorer's dominance with 60 million downloads within nine months. In November 2017, Firefox began incorporating new technology under the code name "Quantum" to promote parallelism and a more intuitive user interface.

Firefox usage share grew to a peak of 32.21% in November 2009, with Firefox 3.5 overtaking Internet Explorer 7, although not all versions of Internet Explorer as a whole; its usage then declined in competition with Google Chrome. As of February 2025, according to StatCounter, it had a 6.36% usage share on traditional PCs (i.e. as a desktop browser), making it the fourth-most popular PC web browser after Google Chrome (65%), Microsoft Edge (14%), and Safari (8.65%).

Hypertext Markup Language (HTML) is the standard markup language for documents designed to be displayed in a web browser. It defines the content and structure of web content. It is often assisted by technologies such as Cascading Style Sheets (CSS) and scripting languages such as JavaScript.

Web browsers receive HTML documents from a web server or from local storage and render the documents into multimedia web pages. HTML describes the structure of a web page semantically and originally included cues for its appearance.

The first engines for JavaScript were mere interpreters of the source code, but all relevant modern engines use just-in-time compilation for improved performance. JavaScript engines are typically developed by web browser vendors, and every major browser has one. In a browser, the JavaScript engine runs in concert with the rendering engine via the Document Object Model and Web IDL bindings. However, the use of JavaScript engines is not limited to browsers; for example, the V8 engine is a core component of the Node.js runtime system. They are also called ECMAScript engines, after the official name of the specification. With the advent of WebAssembly, some engines can also execute this code in the same sandbox as regular JavaScript code.

WebKit is a browser engine primarily used in Apple's Safari web browser, as well as all web browsers on iOS and iPadOS. WebKit is also used by the PlayStation consoles starting with the PS3, the Tizen mobile operating systems, the Amazon Kindle e-book reader, Nintendo consoles starting with the 3DS Internet Browser, GNOME Web, and the discontinued BlackBerry Browser.

WebKit started as a fork of the KHTML and KJS libraries from KDE, and has since been further developed by KDE contributors, Apple, Google, Nokia, Bitstream, BlackBerry, Sony, Igalia, and others. WebKit supports macOS, Windows, Linux, and various other Unix-like operating systems. On April 3, 2013, Google announced that it had forked WebCore, a component of WebKit, to be used in future versions of Google Chrome under the name Blink. Since version 15 in May 2013, Opera web browser has dropped its own Presto layout engine in favor of WebKit as implemented by Google in the Chromium project.

Blink is a browser engine developed as part of the free and open-source Chromium project. Blink is by far the most-used browser engine, due to the market share dominance of Google Chrome and the fact that many other browsers are based on the Chromium code.

To create Chrome, Google initially chose to use Apple's WebKit engine. However, Google needed to make substantial changes to its code to support Chrome's novel multi-process browser architecture. Over the course of several years, the divergence from Apple's version increased, so Google decided to officially fork its version as Blink in 2013.

KHTML is a discontinued browser engine that was developed by the KDE project. It originated as the engine of the Konqueror browser in the late 1990s, but active development ceased in 2016. It was officially discontinued in 2023.

Built on the KParts framework and written in C++, KHTML had relatively good support for Web standards during its prime. Engines forked from KHTML are used by most of the browsers that are widely used today, including WebKit (Safari) and Blink (Google Chrome, Chromium, Microsoft Edge, Opera, Vivaldi, Opera GX, Opera Mini, Opera Mobile, Yandex Browser, Orion, Arc (On iOS), Epiphany, Midori, Konqueror, Otter Browser, Dooble, Epic Privacy Browser, Slimjet, Comodo Dragon, SRWare Iron, Cốc Cốc, Torch Browser, Orbitum, UC Browser, Kiwi Browser, Samsung Internet, Bromite, Blisk, Colibri Browser, Min Browser, Ungoogled Chromium, Iridium Browser, Avast Secure Browser, AVG Secure Browser and Brave).

Gecko is a browser engine developed by Mozilla. It is used in the Firefox browser, the Thunderbird email client, and in a discontinued state on AOL's Netscape 6, Netscape 7, Netscape Browser and Netscape Navigator 9; this is alongside many other projects.

Gecko is designed to support open Internet standards, and is used by different applications to display web pages and, in some cases, an application's user interface itself (by rendering XUL). Gecko offers a rich programming API that makes it suitable for a wide variety of roles in Internet-enabled applications, such as web browsers, content presentation, and client/server.

Firefox for Android is a web browser developed by Mozilla for Android smartphones and tablet computers. As with its desktop version, it uses the Gecko layout engine, and supports features such as synchronization with Firefox Sync, and add-ons.

The initial version of Firefox for Android was codenamed Fennec and branded Firefox for mobile; it initially supported Maemo and Android before supporting MeeGo and Firefox OS as well. Support for Maemo was later dropped. In 2020, a redesigned version of Firefox for Android (codenamed Fenix, and also branded as Firefox Daylight) was released, which introduced a new internal architecture and user interface inspired by Firefox Focus, new privacy features, and switching to curated WebExtensions for add-ons.

The project that became Firefox today began as an experimental branch of the Mozilla Suite called m/b (or mozilla/browser). Firefox retains the cross-platform nature of the original Mozilla browser, using the XUL user interface markup language. The use of XUL made it possible to extend the browser's capabilities through the use of extensions and themes. The development and installation processes of these add-ons raised security concerns, and with the release of Firefox 0.9, the Mozilla Foundation opened a Mozilla Update website containing "approved" themes and extensions. The use of XUL sets Firefox apart from other browsers, including other projects based on Mozilla's Gecko layout engine and most other browsers, which use interfaces native to their respective platforms (Galeon and Epiphany use GTK+, K-Meleon uses MFC, and Camino uses Cocoa). Many of these projects started before Firefox, and may have served as inspiration.

Hyatt, Ross, Hewitt and Chanial developed their browser to combat the perceived software bloat of the Mozilla Suite (codenamed, internally referred to, and continued by the community as SeaMonkey), which integrated features such as IRC, mail, news, and WYSIWYG HTML editing into one internet suite. After it was sufficiently developed, binaries for public testing appeared in September 2002 under the name Phoenix. This name carried the implication of the mythical firebird that rose triumphantly from the ashes of its dead predecessor, in this case Netscape Navigator which lost the "First browser war" to Microsoft's Internet Explorer. The name Mozilla began as the internal codename for the original 1994 Netscape Navigator browser aiming to displace NCSA Mosaic as the world's most popular web browser. The name for this would-be "Mosaic killer" was meant to evoke the building-crushing Godzilla.

ChromiumOS (formerly styled as Chromium OS) is a free and open-source Linux distribution designed for running web applications and browsing the World Wide Web. It is the open-source version of ChromeOS, a Linux distribution made by Google.

ChromiumOS is based on the Linux kernel, like ChromeOS, but its principal user interface is the Chromium web browser rather than the Google Chrome browser. ChromiumOS also includes the Portage package manager, which was originally developed for Gentoo Linux. Because ChromiumOS and ChromeOS use a browser engine for the user interface, they are oriented toward web applications rather than application software or mobile apps.