Google Chrome
This article is about the web browser. For the operating system, see Google Chrome OS.
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Google Chrome
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Google Chrome is a freeware web browser[7] developed by Google. It used the WebKit layout engine until version 27 and, with the exception of its iOS releases, from version 28 and beyond uses the WebKit fork Blink.[8][9][10] It was first released as a beta version forMicrosoft Windows on September 2, 2008, and as a stable public release on December 11, 2008.
Net Applications has indicated that Chrome is the third-most popular web browser when it comes to the size of its user base, behindInternet Explorer and Firefox.[11] StatCounter, however, estimates that Google Chrome has a 39% worldwide usage share of web browsersmaking it the most widely used web browser in the world.[12]
In September 2008, Google released the majority of Chrome's source code as an open source project called Chromium,[13][14] on which Chrome releases are still based. Notable components that are not open source are the built in PDF viewer and the built in Flash player.
History
Google's Eric Schmidt opposed the development of an independent web browser for six years. He stated that "at the time, Google was a small company," and he did not want to go through "bruising browser wars." After co-founders Sergey Brin and Larry Page hired several Mozilla Firefox developers and built a demonstration of Chrome, however, Schmidt admitted that "It was so good that it essentially forced me to change my mind.
Announcement
The release announcement was originally scheduled for September 3, 2008, and a comic by Scott McCloud was to be sent to journalists and bloggers explaining the features within the new browser.[16] Copies intended for Europe were shipped early and German blogger Philipp Lenssen of Google Blogoscoped[17] made a scanned copy of the 38-page comic available on his website after receiving it on September 1, 2008.[18] Google subsequently made the comic available on Google Books[19] and mentioned it on their official blog along with an explanation for the early release
Public release
The browser was first publicly released for Microsoft Windows (XP and later versions) on September 2, 2008 in 43 languages, officially a beta version.[21]
On the same day, a CNET news item[22] drew attention to a passage in the Terms of Service statement for the initial beta release, which seemed to grant to Google a license to all content transferred via the Chrome browser. This passage was inherited from the general Google terms of service.[23]Google responded to this criticism immediately by stating that the language used was borrowed from other products, and removed this passage from the Terms of Service.[7]
Chrome quickly gained about 1% usage share.[20][24][25][26] After the initial surge, usage share dropped until it hit a low of 0.69% in October 2008. It then started rising again and by December 2008, Chrome again passed the 1% threshold.[27]
In early January 2009, CNET reported that Google planned to release versions of Chrome for OS X and Linux in the first half of the year.[28] The first official Chrome OS X and Linux developer previews[29] were announced on June 4, 2009 with a blog post[30] saying they were missing many features and were intended for early feedback rather than general use.
In December 2009, Google released beta versions of Chrome for OS X and Linux.[31][32] Google Chrome 5.0, announced on May 25, 2010, was the first stable release to support all three platforms.[33]
Chrome was one of the twelve browsers offered to European Economic Area users of Microsoft Windows in 2010
Development
Chrome was assembled from 25 different code libraries from Google and third parties such as Mozilla's Netscape Portable Runtime, Network Security Services, NPAPI, Skia Graphics Engine,SQLite, and a number of other open-source projects.[35] The V8 JavaScript virtual machine was considered a sufficiently important project to be split off (as was Adobe/Mozilla's Tamarin) and handled by a separate team in Denmark coordinated by Lars Bak at Aarhus. According to Google, existing implementations were designed "for small programs, where the performance and interactivity of the system weren't that important", but web applications such as Gmail "are using the web browser to the fullest when it comes to DOM manipulations and JavaScript", and therefore would significantly benefit from a JavaScript engine that could work faster.
Chrome uses the Blink rendering engine to display web pages. Based on WebKit 2, Blink only uses WebKit's "WebCore" components while substituting all other components, such as its own multi-process architecture in place of WebKit's native implementation.[36]
Chrome is internally tested with unit testing, "automated user interface testing of scripted user actions", fuzz testing, as well as WebKit's layout tests (99% of which Chrome is claimed to have passed), and against commonly accessed websites inside the Google index within 20–30 minutes.[19]
Google created Gears for Chrome, which added features for web developers typically relating to the building of web applications, including offline support.[19] However, Google phased out Gears in favor of HTML5.[37]
On January 11, 2011 the Chrome product manager, Mike Jazayeri, announced that Chrome would remove H.264 video codec support for its HTML5 player, citing the desire to bring Google Chrome more in line with the currently available open codecs available in the Chromium project, which Chrome is based on.[38] Despite this, on November 6, 2012, Google released a version of Chrome on Windows which added hardware-accelerated H.264 video decoding.[39] As of January 2013, there has been no further announcement about the future of Chrome H.264 support.
On February 7, 2012, Google launched Google Chrome Beta for Android 4.0 devices.[40] On many new devices with Android 4.1 and later preinstalled, Chrome is the default browser.[41]
On April 3, 2013, Google announced that it would fork the WebCore component of WebKit to form its own layout engine known as Blink. The aim of Blink will be to give Chrome's developers more freedom in implementing its own changes to the engine, and to allow its codebase to be trimmed of code that is unnecessary or unimplemented by Chrome.
Enterprise deployment
In December 2010 Google announced that to make it easier for businesses to use Chrome they would provide an official Chrome MSI package. For business use it is helpful to have full-fledged MSI packages that can be customized via transform files (.mst) - but the MSI provided with Chrome is only a very limited MSI wrapper fitted around the normal installer, and many businesses find that this arrangement does not meet their needs.[42] The normal downloaded Chrome installer puts the browser in the user's local app data directory and provides invisible background updates, but the MSI package will allow installation at the system level, providing system administrators control over the update process[43] — it was formerly possible only when Chrome was installed usingGoogle Pack. Google also created group policy objects to fine tune the behavior of Chrome in the business environment, for example setting automatic updates interval, disable auto-updates, a home page and to workaround their basic Windows design flaws and bugs if it comes to roaming profiles support, etc.[44] Until version 24 the software is known not to be ready for enterprise deployments with roaming profiles or Terminal Server/Citrix environments
Chromium
In September 2008, Google released a large portion of Chrome's source code as an open source project called Chromium. This move enabled third-party developers to study the underlying source code and to help port the browser to the OS X and Linux operating systems. The Google-authored portion of Chromium is released under the permissive BSD license.[46] Other portions of the source code are subject to a variety of open source licenses.[47] Chromium is similar to Chrome, but lacks built-in automatic updates, built-in PDF reader and built-in Flash player, as well as Google branding and has a blue-colored logo instead of the multicolored Google logo.[48][49] Chromium does not implement user RLZ tracking.
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