Google Chrome

Google Chrome is a web browser developed by Google that uses the WebKit layout engine and application framework. It was first released as a beta version for Microsoft Windows on 2 September 2008, and the public stable release was on 11 December 2008. The name is derived from the graphical user interface frame, or "chrome", of web browsers. As of December 2009[update], Chrome was the third most widely used browser, with 4.63% of worldwide usage share of web browsers.
In September 2008, Google released the entire source code of Chrome, including its V8 JavaScript engine, as an open source project entitled Chromium. This move enabled third-party developers to study the underlying source code and help port the browser to Mac OS X and Linux. A Google spokesperson also expressed hope that other browsers would adopt V8 to help web applications. The Google-authored portion of Chromium is released under the permissive BSD license, which allows portions to be incorporated into both open source and proprietary software programs. Other portions of the source code are subject to a variety of open-source licenses. Chromium implements the same feature set as Chrome, but without Google branding and automatic updates, and it has a slightly different logo.
History:
Announcement
The release announcement was originally scheduled for 3 September 2008, and a comic by Scott McCloud was to be sent to journalists and bloggers explaining the features of and motivations for the new browser. Copies intended for Europe were shipped early and German blogger Philipp Lenssen of Google Blogoscoped made a scanned copy of the 38-page comic available on his website after receiving it on 1 September 2008. Google subsequently made the comic available on Google Books 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 only) on 2 September 2008 in 43 languages, officially a beta version. Chrome quickly gained about 1% market share despite Mac OS X and Linux versions still being under development. After the initial surge, usage share dropped until it hit a low of 0.69% in October 2008. It then started rising again until by December 2008, Chrome again passed the 1% threshold.
In late 2008, a message saying that a "test shell" is available to build on Linux was placed in the Chromium project's developer wiki. Some tried this shell, which apparently lacked many features, but appeared to function quite well in rendering web sites (including JavaScript). In early January 2009, CNET reported that Google planned to release versions for Mac OS X and Linux in the first half of the year. By March 2009, it was possible to build a pre-alpha version of the Chromium browser, which looked similar to the Windows release, but was still very far from complete.
The first official Chrome Mac OS X and Linux developer previews were announced on 4 June 2009 with a blog post saying they were missing many features and were intended for early feedback rather than general use. On 9 October 2009, Google CEO Eric Schmidt stated that Chrome for Mac would be released "in a couple of months." On 30 November 2009, it was reported that the Mac OS X beta would be available by the end of 2009, lacking such features as App Mode, a bookmark manager, 64-bit support, Bookmark Sync, and extensions.
Official betas for Mac OS X and Linux were released on 8 December 2009.
Development
Chrome was assembled from 25 different code libraries from Google and third parties such as Netscape. The 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 WebKit rendering engine to display web pages, on advice from the Android team. Like most browsers, Chrome was extensively tested internally before release with unit testing, "automated user interface testing of scripted user actions" and fuzz testing, as well as WebKit's layout tests (99% of which Chrome is claimed to have passed). New browser builds are automatically tested against tens of thousands of commonly accessed websites inside of the Google index within 20–30 minutes.
Chrome includes Gears, which adds features for web developers typically relating to the building of web applications (including offline support).
The first release of Google Chrome passed the Acid1 and Acid2 tests, but not Acid3. On Acid3 it scored 79 out of the 100 subtests, higher than contemporary versions of Internet Explorer 7 (14/100), Firefox 3 (71/100), and Safari 3 (75/100); but lower than Opera 9 (83/100). When compared with contemporary development builds of Firefox, Internet Explorer, Opera, and Safari, Chrome scored lower than Firefox 3.1 Beta 1 (85/100), Opera (100/100), and Safari 4 (100/100); but still higher than Internet Explorer (21/100). However, version 2.0 of Google Chrome passed all 100 subtests (but still failed the link test).[citation needed] The current stable version (3.0) scores 100/100 but shows a 'X' in the upper right corner because downloadable fonts are disabled until security concerns surrounding them can be resolved. Development builds of Google Chrome starting with version 4.0.249.4 and higher pass all aspects of the Acid 3 test, including the link test and downloadable fonts.
On 7 July 2009, Google announced plans for a Google Chrome OS based on the Chrome browser and Linux.
Google released Chrome 2.0 on 21 May 2009, citing increased speed and stability. New features included form autofill, an improved New Tab Page, and full screen mode.