WebKit is a browser engine developed by Apple and primarily used in its Safari web browser, as well as all iOS web browsers. WebKit is also used by the BlackBerry Browser, PlayStation consoles beginning from the PS3, the Tizen mobile operating systems, and a browser included with the Amazon Kindle e-book reader. WebKit's C++ application programming interface (API) provides a set of classes to display Web content in windows, and implements browser features such as following links when clicked by the user, managing a back-forward list, and managing a history of pages recently visited.
The WebKit logo, as of 2015
|Developer(s)||Apple Inc., Adobe Systems, Sony, KDE, Igalia, and others|
|Initial release||November 4, 1998 (KHTML released)|
June 7, 2005 (WebKit sourced)
|Operating system||macOS, Linux|
According to Apple, some changes involved OS X-specific features (e.g., Objective-C, KWQ, OS X calls) that are absent in KDE's KHTML, which called for different development tactics.
The exchange of code between WebCore and KHTML became increasingly difficult as the code base diverged because both projects had different approaches in coding and code sharing. At one point KHTML developers said they were unlikely to accept Apple's changes and claimed the relationship between the two groups was a "bitter failure". Apple submitted their changes in large patches containing very many changes with inadequate documentation, often to do with future additions. Thus, these patches were difficult for the KDE developers to integrate back into KHTML. Also, Apple had demanded that developers sign non-disclosure agreements before looking at Apple's source code and even then they were unable to access Apple's bug database.
During the publicized "divorce" period, KDE developer Kurt Pfeifle (pipitas) posted an article claiming KHTML developers had managed to backport many (but not all) Safari improvements from WebCore to KHTML, and they always appreciated the improvements coming from Apple and still do so. The article also noted Apple had begun to contact KHTML developers about discussing how to improve the mutual relationship and ways of future cooperation. In fact, the KDE project was able to incorporate some of these changes to improve KHTML's rendering speed and add features, including compliance with the Acid2 rendering test.
Following the story of the fork's appearance in the news, Apple released changes of the source code of WebKit fork in a public revision-control repository. Since the transfer of the source code into a public Concurrent Versions System (CVS) repository, Apple and KHTML developers have had increasing collaboration. Many KHTML developers have become reviewers and submitters for WebKit revision control repository.
The WebKit team had also reversed many Apple-specific changes in the original WebKit code base and implemented platform-specific abstraction layers to make committing the core rendering code to other platforms significantly easier.
In July 2007, Ars Technica reported that the KDE team would move from KHTML to WebKit. Instead, after several years of integration, KDE Development Platform version 4.5.0 was released in August 2010 with support for both WebKit and KHTML, and development of KHTML continues.
In mid-December 2005, support for Scalable Vector Graphics (SVG) was merged into the standard build and in early January 2006 the source code was migrated from Concurrent Versions System (CVS) to Subversion (SVN).
Beginning in early 2007, the development team began to implement Cascading Style Sheets (CSS) extensions, including animation, transitions and both 2D and 3D transforms; such extensions were released as working drafts to the World Wide Web Consortium (W3C) in 2009 for standardization.
In November 2007, the project announced that it had added support for media features of the HTML5 draft specification, allowing embedded video to be natively rendered and script-controlled in WebKit.
The week after Hyatt announced WebKit's open-sourcing, Nokia announced that it had ported WebKit to the Symbian operating system and was developing a browser based on WebKit for mobile phones running S60. Named Web Browser for S60, it was used on Nokia, Samsung, LG, and other Symbian S60 mobile phones. Apple has also ported WebKit to iOS to run on the iPhone, iPod Touch, and iPad, where it is used to render content in the device's web browser and e-mail software. The Android mobile phone platform used WebKit (and later versions its Blink fork) as the basis of its web browser and the Palm Pre, announced January 2009, has an interface based on WebKit. The Amazon Kindle 3 includes an experimental WebKit based browser.
In June 2007, Apple announced that WebKit had been ported to Microsoft Windows as part of Safari. However, this port is no longer maintained.
WebKit has also been ported to several toolkits that support multiple platforms, such as the GTK toolkit for Linux, under the name WebKitGTK which is used by GNOME Web, Adobe Integrated Runtime, Enlightenment Foundation Libraries (EFL), and the Clutter toolkit. Qt Software included a WebKit port in the Qt 4.4 release as a module called QtWebKit (since superseded by Qt WebEngine, which uses Blink instead). The Iris Browser on Qt also used WebKit. The Enlightenment Foundation Libraries (EFL) port – EWebKit – was developed (by Samsung and ProFusion) focusing the embedded and mobile systems, for use as stand alone browser, widgets-gadgets, rich text viewer and composer. The Clutter port is developed by Collabora and sponsored by Robert Bosch GmbH.
There was also a project synchronized with WebKit (sponsored by Pleyo) called Origyn Web Browser, which provided a meta-port to an abstract platform with the aim of making porting to embedded or lightweight systems quicker and easier. This port is used for embedded devices such as set-top boxes, PMP and it has been ported into AmigaOS, AROS and MorphOS. MorphOS version 1.7 is the first version of Origyn Web Browser (OWB) supporting HTML5 media tags.
Web Platform for Embedded
Web Platform for Embedded (WPE) is a WebKit port designed for embedded applications; it further improves the architecture by splitting the basic rendering functional blocks into a general-purpose routines library (libwpe), platform backends, and engine itself (called WPE WebKit). The GTK port, albeit self-contained, can be built to use these base libraries instead of its internal platform support implementation. The WPE port is currently maintained by Igalia.
Forking by Google
An optimizing just-in-time (JIT) compiler named FTL was announced on May 13, 2014. It uses LLVM to generate optimized machine code. "FTL" stands for "Fourth-Tier-LLVM", and unofficially for faster-than-light, alluding to its speed. As of February 15, 2016, the backend of FTL JIT is replaced by "Bare Bones Backend" (or B3 for short).
- "'(fwd) Greetings from the Safari team at Apple Computer' – MARC". Lists.kde.org. January 7, 2003. Archived from the original on February 9, 2015. Retrieved May 2, 2017.
- "Safari is released to the world". Donmelton.com. Retrieved January 13, 2013.
- "WebKit Nightly Builds". WebKit.org. Archived from the original on April 3, 2016. Retrieved May 27, 2014.
- "Code Style Guidelines". WebKit.org. Apple, Inc. Archived from the original on May 1, 2017. Retrieved May 2, 2017.
- "WebKit Download". Retrieved August 14, 2018.
- Licensing WebKit | WebKit
- "The WebKit Open Source Project". Archived from the original on April 10, 2012. Retrieved April 7, 2012.
- Stachowiak, Maciej (November 9, 2008). "Companies and Organizations that have contributed to WebKit". WebKit Wiki. Retrieved November 17, 2008.
- "The WebKit Open Source Project – Getting the Code". Webkit.org. Archived from the original on March 6, 2016. Retrieved December 27, 2010.
- Barth, Adam (April 3, 2013). "Chromium Blog: Blink: A rendering engine for the Chromium project". Blog.chromium.org. Archived from the original on April 4, 2013. Retrieved June 14, 2013.
- Lawson, Bruce. "Bruce Lawson's personal site: Hello Blink". Brucelawson.co.uk. Retrieved June 14, 2013.
- "Open Source – WebKit". Apple. Archived from the original on March 11, 2009. Retrieved March 5, 2009.
- "Apple's "WebKit" is now a Registered Trademark in the US". Archived from the original on March 9, 2013. Retrieved March 7, 2013.
- Melton, Don (August 25, 2011). "Attention Internets! WebKit is not 10 years old today. That happened on June 25. I know the date because that's when I started the project". Twitter. Retrieved October 13, 2011.
- KWQ (pronounced "quack") is an implementation of the subset of Qt required to make KHTML work on OS X. It is written in Objective C++.
- "Safari and KHTML again". kdedevelopers.org. April 30, 2005. Archived from the original on March 3, 2006. Retrieved February 20, 2010.
- "So, when will KHTML merge all the WebCore changes?". kdedevelopers.org. Archived from the original on May 29, 2010. Retrieved February 20, 2010.
- "The bitter failure named 'safari and khtml'". Archived from the original on April 15, 2015.
- "Open-source divorce for Apple's Safari?". Archived from the original on July 7, 2009.
- "WebCore open source changes". Archived from the original on May 27, 2016. Retrieved May 14, 2016.
- "WebCore – KHTML – Firefox: Know your facts!". Archived from the original on February 10, 2009.
- "Konqueror now passes Acid2". Archived from the original on June 21, 2017.
- Molkentin, Daniel (June 7, 2005). "Apple Opens WebKit CVS and Bug Database". KDE News. Archived from the original on July 15, 2009. Retrieved January 16, 2007.
- "Ars at WWDC: Interview with Lars Knoll, creator of KHTML". Archived from the original on May 31, 2008.
- Unrau, Troy (July 23, 2007). "The unforking of KDE's KHTML and WebKit". Ars Technica. Archived from the original on September 30, 2007. Retrieved July 30, 2007.
- "KDE Development Platform 4.5.0 gains performance, stability, new high-speed cache and support for WebKit". Archived from the original on March 14, 2011.
- "Next Generation KDE Technologies Ported to WebCore". Archived from the original on October 13, 2007.
- "CSS Transforms". Archived from the original on January 13, 2017.
- "CSS3 Animations". Archived from the original on February 21, 2009.
- Koivisto, Antti (November 12, 2007). "HTML5 Media Support". Surfin' Safari blog. Archived from the original on January 13, 2017.
- "Announcing SquirrelFish". Archived from the original on January 27, 2017.
- "SquirrelFish project".
- "Introducing SquirrelFish Extreme". Archived from the original on November 26, 2016.
- "Changeset 40439 – WebKit". Trac.webkit.org. January 30, 2009. Retrieved December 27, 2010.
- "WebKit2 wiki". Webkit.org. Retrieved August 3, 2012.
- "Announcing WebKit2". Webkit.org. Archived from the original on April 23, 2011. Retrieved December 27, 2010.
- "Introducing the Nokia N9: all it takes is a swipe! |Nokia Conversations – The official Nokia Blog". Nokia Corporation. Archived from the original on June 24, 2011. Retrieved June 21, 2011.
- "Source code repository for public parts of Safari 5.1". The WebKit Open Source Project. Retrieved July 20, 2011.
- "WWDC 2014 Session 206 - Introducing the Modern WebKit API - ASCIIwwdc".
- "132399 – Move the legacy WebKit API into WebKitLegacy.framework and move it inside WebKit.framework". Webkit.org.
- "Renaming Directories and Project Files to Match Framework Names". Webkit.org.
- "Nokia S60 Webkit Browser". Archived from the original on December 6, 2005.
- "Google Chrome, Google's Browser Project". Archived from the original on September 2, 2008.
- "Comic describing the Google Chrome Project". Archived from the original on September 3, 2008.
- "PS3、ファームウェアv4.10からWebKitへ。 - あまたの何かしら。". D.hatena.ne.jp. February 8, 2012. Archived from the original on October 14, 2012. Retrieved January 13, 2013.
- "Epiphany Mailing list – Announcement: The Future of Epiphany". Archived from the original on February 14, 2012.
- Chen, Brian X. "HP Launches WebOS-Powered Tablet, Phones | Gadget Lab". Wired.com. Archived from the original on April 10, 2014. Retrieved January 13, 2013.
- "A Brand New Steam". Archived from the original on December 30, 2010.
- "100 Million Club (H1 2010 update)". VisionMobile. Archived from the original on March 1, 2011. Retrieved March 1, 2011.
- "StatCounter". StatCounter. Archived from the original on May 26, 2012. Retrieved April 14, 2015.
- Stachowiak, Maciej (January 10, 2007). "The Obligatory iPhone Post". Surfin' Safari weblog. Archived from the original on February 19, 2008. Retrieved January 24, 2008.
- "Android Uses WebKit". Archived from the original on January 13, 2017. Retrieved January 12, 2017.
- "WebKit in the News". WebKit. November 13, 2007. Retrieved November 17, 2018.
- "The Amazing Rise of WebKit Mobile". gigaom.com. November 13, 2007. Retrieved November 17, 2018.
- "Palm Pre in-depth impressions, video, and huge hands-on gallery". Archived from the original on January 13, 2017.
- Topolsky, Joshua. "New Amazon Kindle announced: $139 WiFi-only version and $189 3G model available August 27th in the US and UK". Archived from the original on January 13, 2017.
- "WebKitGTK+ project website". Archived from the original on January 30, 2017.
- "Alp Toker – WebKit/Gtk+ is coming". Archived from the original on March 25, 2008.
- "WebKitClutter project website".
- "QT WebKit". Archived from the original on August 3, 2009.
- "ProFusion | Home". Profusion.mobi. Retrieved January 13, 2013.
- "pleyo". Archived from the original on March 25, 2008.
- "See OWB forge". Archived from the original on May 9, 2008.
- "AmigaOS OWB official page".
- "Amiga – Powering through, dead or alive!". amigaweb.net. Archived from the original on May 2, 2008. Retrieved June 2, 2010.
- "AROS OWB developer page". Archived from the original on March 4, 2009.
- "Origyn Web Browser for MorphOS". Fabian Coeurjoly. Archived from the original on March 17, 2010. Retrieved January 4, 2010.
- Holwerda, Thom (March 8, 2010). "Origyn Web Browser 1.7 Supports HTML5 Media, More". OSNews. Archived from the original on March 12, 2010. Retrieved March 8, 2010.
- "WebKit developers planning Chromium extraction". The H. Archived from the original on April 7, 2013. Retrieved April 9, 2013.
- Stachowiak, Maciej (September 25, 2008). "Full Pass Of Acid3". Surfin' Safari – The WebKit Blog. Archived from the original on September 29, 2008. Retrieved September 29, 2008.
- "Introducing the WebKit FTL JIT". Archived from the original on January 19, 2017.
- "Introducing the B3 JIT Compiler". Archived from the original on May 3, 2017.