Google Chrome

Google Chrome is a web browser developed by Google that uses the WebKit layout engine. It was first released as a beta version for Microsoft Windows on September 2, 2008, and the public stable release was on December 11, 2008. The name is derived from the graphical user interface frame, or "chrome", of web browsers.[citation needed] As of December 2011, Chrome is the second most widely used browser, having recently overtaken Mozilla Firefox, with 27.27% worldwide usage share of web browsers and is the most popular browser in South America,[1] according to StatCounter.[2][3]

In September 2008, Google released a large portion of Chrome's source code, including its V8 JavaScript engine, as an open source project entitled Chromium.[4][5] This move enabled third-party developers to
study the underlying source code and to help port the browser to the Mac OS X and Linux operating systems. Google also expressed hope that other browsers would adopt the V8 JavaScript engine to improve web application performance.[6] The Google-authored portion of Chromium is released under the permissive BSD license,[7] which allows portions to be incorporated into both open source and closed source software programs.[8] Other portions of the source code are subject to a variety of open source licenses.[9] Chromium implements a similar feature set as Chrome, but lacks built-in automatic updates, built-in PDF reader and Google branding, and has a blue-colored logo instead of the multicolored Google logo


History

For six years, Google's Chief Executive Eric Schmidt was against the idea of building an independent web browser. He stated that "At the time, Google was a small company", and he did not want to go through "bruising browser wars". However, after co-founders Sergey Brin and Larry Page hired several Mozilla Firefox developers and built a demonstration of Chrome, Schmidt admitted that "It was so good that it essentially forced me to change my mind".[12]
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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.[13] Copies intended for Europe were shipped early and German blogger Philipp Lenssen of Google Blogoscoped[14] made a scanned copy of the 38-page comic available on his website after receiving it on September 1, 2008.[15] Google subsequently made the comic available on Google Books[16] and mentioned it on their official blog along with an explanation for the early release.[17]
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Public release

An early version of Chromium for Linux, explaining the difference between Chrome and Chromium

The browser was first publicly released for Microsoft Windows (XP and later versions) on September 2, 2008 in 43 languages, officially a beta version.[18] Chrome quickly gained about 1% market share despite being only available for Microsoft Windows at that time.[17][19][20][21] 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.[22]

In early January 2009, CNET reported that Google planned to release versions of Chrome for Mac OS X and Linux in the first half of the year.[23] The first official Chrome Mac OS X and Linux developer previews[24] were announced on June 4, 2009 with a blog post[25] 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 Mac OS X and Linux.[26][27] Google Chrome 5.0, announced on May 25, 2010, was the first stable release to support all three platforms.[28]

Chrome was one of the twelve browsers offered to European Economic Area users of Microsoft Windows in 2010.[29]
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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, as well as SQLite and a number of other open-source projects.[30] 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.

Usage share of web browsers (excluding IE) according to StatCounter[31]

Chrome uses the WebKit rendering engine to display web pages, on advice from the Android team.[16] 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 the Google index within 20–30 minutes.[16]

The Windows version of Chrome includes Gears, which adds features for web developers typically relating to the building of web applications (including offline support).[16] However, Google is phasing out Gears in favor of HTML5.[32]

On January 11, 2011 the Chrome Product manager, Mike Jazayeri, announced that Chrome will no longer support H.264 video codec for its HTML5 player, citing the desire to bring Google Chrome more inline with the currently available open codecs available in the Chromium project, which Chrome is based on.[33] As of January 2012, there has been no announcement yet of which future version of Chrome will actually implement the removal of H.264 support.
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Enterprise Deployment

In December 2010 Google announced that to make deploying Chrome easier in a business environment they would provide an official Chrome MSI package. For Enterprise deployments it's important to have full-fledged MSI packages that can be customized via transform files, but the provided MSI is only a very limiting MSI wrapper around the normal installer that does not fulfill all Enterprise needs.[34] 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[35] – it was formerly possible only when Chrome was installed using Google Pack. Google also created Group Policies 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.[36] Until version 18 the software is known not to be ready for Enterprise deployments with roaming profiles.[37]
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Pre-releases

In addition to the stable build of Google Chrome, Google makes several pre-release versions, or "early release channels" available. These are referred to as channels because the browser is dynamically updated and are designated "Beta" "Dev" and "Canary". The Chrome Beta build is intended to be tested by anyone and is slightly newer than the stable version of chrome. The Dev, or developer build, is intended for users with software testing or programming experience. The Canary build is an automatically created version of the latest software from the parent Chromium project, which is not tested prior to release. As a result Google blocks the ability to set the Canary build as the user's default browser and allows it to be installed alongside another version of Chrome.[38]
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Chromium

While Chromium is the parent project of Google Chrome, there are some key differences that set the two apart. Chromium, unlike the pre-release versions of Chrome, is updated almost every day, but does not include the built-in Flash Player (it has to be downloaded separately) and Google Auto-updater found in Chrome. Chromium also has a less restrictive end user license than the compiled builds of Chrome, and does not implement user RLZ tracking, a privacy concern.[39][40][41]
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Release history

Legend:Color Meaning
Red Old release
Green Current stable release
Blue Current beta release
Purple Current dev release


Note: All versions support Windows. Mac and Linux are supported starting with version 5.0.375.Major version Release date WebKit version[42] V8 engine version[43] Significant changes
0.2.149 2008-09-02 522 0.3 First release.[44]
0.3.154 2008-10-29 Improved plugin performance and reliability. Spell checking for input fields. Improved web proxy performance and reliability. Tab and window management updates.
0.4.154 2008-11-24 525 Bookmark manager with import and export support. Privacy section added to the application options. New blocked popup notification. Security fixes.
1.0.154 2008-12-11 528 First stable release.
2.0.172 2009-05-24 530 0.4 35% faster JavaScript on the SunSpider benchmark. Mouse wheel support. Full-screen mode. Full-page zoom. Form autofill. Sort bookmarks by title. Tab docking to browser and desktop edges. Basic Greasemonkey support.[45]
3.0.195 2009-10-12 532 1.2 New "new tab" page for improved customization. 25% faster JavaScript. HTML5 video and audio tag support. Lightweight theming.
4.0.249 2010-01-25 532.5 1.3 Extensions. Bookmark synchronization. Enhanced developer tools. Improved HTML5 support. Performance improvements. Full ACID3 pass. HTTP byte range support. Increased security. Experimental new anti-reflected-XSS feature called "XSS Auditor".[46]
4.1.249 2010-03-17 Translate infobar. New privacy features. Disabled XSS Auditor.[47]
5.0.375 2010-05-21 533 2.1 Improved JavaScript performance. Browser preference synchronizing. Increased HTML5 support (Geolocation APIs, App Cache, web sockets, and file drag-and-drop). Revamped bookmark manager. Adobe Flash Player integrated.[48][49]
6.0.472 2010-09-02 534.3 2.2 Updated and more streamlined UI with simplified Omnibox. New tab page. Merged menu buttons. Form Autofill. Expanded synchronization support to include extensions and Autofill data. Support for WebM videos. Improvements for performance and stability.[50] Built-in PDF support (disabled by default).[51]
7.0.517 2010-10-21 534.7 2.3.11.22 Primarily a stabilizing release with hundreds of bug fixes. Implemented HTML5 parsing algorithm. File API. Directory upload via input tag. Mac OS X version gained AppleScript support for UI automation.[52] Late binding enabled for SSL sockets: High priority SSL requests are now always sent to the server first. New options for managing cookies. Updated New Tab Page to enable featuring of web applications.
8.0.552 2010-12-02 534.10 2.4.9.19 Chrome Web Store. Built-in PDF viewer that works inside Chrome's sandbox for increased security. Expanded synchronization support to include web applications. Improved plug-in handling.[53] This release added "about:flags" to showcase experimental features such as Chrome Instant, side tabs on Windows, Tabbed Settings, Click to Play, background web applications, Remoting, Disable outdated plug-ins, XSS Auditor, Cloud Print Proxy, GPU-accelerated compositing, WebGL support for the Canvas element, and a "Tab Overview" mode (like Exposé) for Mac OS.
9.0.597 2011-02-03 534.13 2.5.9.6 WebGL enabled by default. Adobe Flash sandboxing on Windows and Chrome Instant (à la Google Instant) option.[54] WebP support.[55] New flags: Print Preview, GPU-accelerated compositing, GPU-accelerated Canvas 2D, Google Native Client, CRX-less Web Apps, Web Page Prerendering, Experimental Extension APIs, Disable hyperlink auditing.
10.0.648 2011-03-08 534.16 3.0.12.30 Google Cloud Print sign-in interface enabled by default. Partially implemented sandboxing of the GPU process.[56][57][58] Faster JavaScript performance due to incorporation of Crankshaft, an improved compiler for V8.[59] Settings pages that open in a tab, rather than a dialog box. Malware reporting and disabling outdated plugins. Password sync added to Chrome Sync and enabled by default. GPU Accelerated Video. Background WebApps. webNavigation extension API.[60]
11.0.696 2011-04-27 534.24 3.1.8.16 HTML5 Speech Input API.[61] Updated icon.[62]
12.0.742 2011-06-07 534.30 3.2.10.21 Hardware accelerated 3D CSS. New Safe Browsing protection against downloading malicious files. Ability to delete Flash cookies from inside Chrome.[63] Launch Apps by name from the Omnibox. Integrated Sync into new settings pages. Improved screen reader support. New warning when hitting Command-Q on Mac.[63] New flags: P2P API. Existing tab on foreground on open. Experimental new tab page. Add grouping to tab context menu. Run PPAPI Flash in the renderer process. Multiple Profiles. Removed Google Gears. Print and Save buttons in the PDF viewer.[64]
13.0.782 2011-08-02 535.1 3.3.10.30 Instant Pages (pre-rendering of webpages).[65] Native print interface and preview (Linux and Windows only). New chrome://flags experiments: Experimental new tab page, Restrict Instant To Search.
14.0.835 2011-09-16 3.4.14.21 Native Client (NaCl) enabled for apps in the Chrome Web Store.[66] Web Audio API. Additional Mac OS X Lion feature support. Sync Encryption for all data. Print Preview on Mac. Experimental Web Request extension API. Experimental Content Settings extension API.[67] DNSSEC validation of HTTPS sites.[68]
15.0.874 2011-10-25 535.2 3.5.10.24 Faster print preview.[69] Redesigned new tab page on by default. JavaScript fullscreen API enabled by default, allowing for full-screen HTML5 video. Inline installation of Chrome Web Store items by verified sites. Omnibox History synchronization.[70] Switched to FFmpeg native VP8 decoder.[71] Extensions integrated into settings pages. GPU Accelerated Canvas 2D disabled.
16.0.912 2011-12-13 535.7 3.6.6.11 Multiple profiles on by default.[70] Optional permissions in Chrome extensions, so the user can opt-in or opt-out of the optional permissions at installation time.[72] Experimental support for side tabs was removed.[73]
17.0.963 2012-01-05 535.11 3.7.12.12 Prompt the user if they want to cancel downloads occurring when the last Incognito Window of a profile is closed. Panels are enabled by default. Adjustable margins supported in Print Preview. Mouse Lock “Allow” permission (given via a prompt) is now saved in content settings per domain. Limited support for touch gestures. Page zoom range increased. Small UI updates include: the absence of a "+" symbol in the New Tab button, CSS styled UI in the options page, replacing native check-boxes and radio buttons. Search engine settings synchronization.[74] Better support for SVG. Added limited support to change User Agent Strings.
18.0.1017 2012-01-24 535.19 3.8.7.1 When a profile is synced, Use Google OAuth userinfo API to get profile information. Added support for manifest_version attribute for extensions. Eliminate drawing glitch on WebUI radio controls. Fixed regression with extension omnibox API where whitespace would get trimmed. Fix page zoom for plug-in documents. Fix race condition in extension service that causes extensions installed. Folders in the wrench menu and application menu are greyed out. Better error handling in audio wave out. Made URL filter for web request API mandatory. Rejects weak RSA and DSA keys when validating certificate chains for HTTPS. Pop-ups opened from a maximized window now unmaximized. Hide panels in presence of full screen app for windows. Provide windows notification of thread termination. Abort in-flight load tasks if the DB has been closed.[citation needed]


Note: Old development builds are not shown here after they go through beta and become stable releases.
[edit]
Features

Google Chrome aims to be secure, fast, simple[75] and stable. There are extensive differences from its peers in Chrome's minimalistic user interface,[16] which is atypical of modern web browsers.[76] For example, Chrome does not render RSS feeds.[77] Chrome's strength is its application performance and JavaScript processing speed, both of which were independently verified by multiple websites to be the swiftest among the major browsers of its time.[78][79] Many of Chrome's unique features had been previously announced by other browser developers, but Google was the first to implement and publicly release them.[80] For example, its most prominent graphical user interface (GUI) innovation, the merging of the address bar and search bar (the Omnibox), was first announced by Mozilla in May 2008 as a planned feature for Firefox.[81] Such a feature was already implemented in Konqueror in 2004.[citation needed]
[edit]
Acid tests

The results of the Acid3 test on Google Chrome 4.0

The first release of Google Chrome passed both the Acid1 and Acid2 tests. Beginning with version 4.0, Chrome passed all aspects of the Acid3 test.[82]
[edit]
Web standards conformance tests

On Ecma International's ECMAScript standards conformance Test 262[83] (version ES5.1 of 2012-01-16), Chrome version 16.0.912.77 scores 423/11181. The beta version, 17.0.963.38, scored 423/11181. The dev version, 18.0.1017.2, scores 40/11181. Lower scores are better, as the figure represents the number of failed tests out of the total number of tests.

On the official CSS 2.1 test suite by standardization organization W3C, WebKit, the Chrome rendering engine, passes 89.75% (89.38% out of 99.59%) of covered CSS 2.1 tests.[84]

On the HTML5 test, Chrome version 16.0.912.63 scored 343 out of 450, with 13 bonus points.[85]
[edit]
Security

Chrome periodically retrieves updates of two blacklists (one for phishing and one for malware), and warns users when they attempt to visit a harmful site. This service is also made available for use by others via a free public API called "Google Safe Browsing API". Google notifies the owners of listed sites who may not be aware of the presence of the harmful software.[16]

Chrome will typically allocate each tab to fit into its own process to "prevent malware from installing itself" and prevent what happens in one tab from affecting what happens in another; however, the actual process-allocation model is more complex.[86] Following the principle of least privilege, each process is stripped of its rights and can compute, but cannot write files or read from sensitive areas (e.g. documents, desktop)—this is similar to the "Protected Mode" used by Internet Explorer on Windows Vista and Windows 7. The Sandbox Team is said to have "taken this existing process boundary and made it into a jail";[87] for example, malicious software running in one tab is supposed to be unable to sniff credit card numbers entered in another tab, interact with mouse inputs, or tell Windows to "run an executable on start-up" and it will be terminated when the tab is closed.[16] This enforces a simple computer security model whereby there are two levels of multilevel security (user and sandbox) and the sandbox can only respond to communication requests initiated by the user.[88] On Linux sandboxing uses the seccomp mode.[89][90]

Typically, plugins such as Adobe Flash Player are not standardized and as such, cannot be sandboxed as tabs can be. These often must run at, or above, the security level of the browser itself. To reduce exposure to attack, plugins are run in separate processes that communicate with the renderer, itself operating at "very low privileges" in dedicated per-tab processes. Plugins will need to be modified to operate within this software architecture while following the principle of least privilege.[16] Chrome supports the Netscape Plugin Application Programming Interface (NPAPI),[91] but does not support the embedding of ActiveX controls.[91] On March 30, 2010 Google announced that the latest development version of Chrome would include Adobe Flash as part of the browser, eliminating the need to download and install it separately. Flash would be kept up to date as part of Chrome's own updates.[92] Java applet support is available in Chrome with Java 6 update 12 and above.[93] Support for Java under Mac OS X was provided by a Java Update released on May 18, 2010.[94]

A private browsing feature called Incognito mode is provided that prevents the browser from storing any history information or cookies from the websites visited. Google Chrome erases the non privacy browsing history periodically to ensure the fastest browsing session possible. Default is set to be done once a month, but can be changed in settings to do more or less frequent. [95] Incognito mode is similar to the private browsing feature in Internet Explorer 8 (and up), Mozilla Firefox 3.5 (and up), Opera 10.5 (and up) and Safari.
[edit]
Security vulnerabilities
See also: Comparison of web browsers#Vulnerabilities

On January 12, 2011 versions of Chrome prior to version 8.0.552.237 were identified by US-CERT as "contain[ing] multiple memory corruption vulnerabilities...By convincing a user to view a specially crafted HTML document, PDF file, or video file, an attacker can cause the application to crash or possibly execute arbitrary code." The vulnerability was subsequently patched and a new stable version was released to the public with Chrome's auto-update mechanism.[96]

No security vulnerabilities in Chrome have been successfully exploited in three years of Pwn2Own.[97]
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Malware blocking

Statistics show that users are four times more likely to be tricked into downloading malware than be compromised by an exploit.[98] In a recent study, Chrome 10 blocked only 13% of malicious URLs, tied for third place with Safari and Firefox. In contrast, Internet Explorer 9 blocked 92% of malware with its URL-based filtering, and 100% with application-based filtering enabled. Internet Explorer 8, in second place, blocked 90% of malware. Exploits that install malware without the user being aware (also referred to as "clickjacking" and "drive-by downloads") were not included in this particular study.[99][100]
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Speed

The JavaScript virtual machine used by Chrome, the V8 JavaScript engine, has features such as dynamic code generation, hidden class transitions, and precise garbage collection.[16] Tests by Google in September 2008 showed that V8 was about twice as fast as Firefox 3.0 and the WebKit nightlies.[citation needed]

Several websites performed benchmark tests using the SunSpider JavaScript Benchmark tool as well as Google's own set of computationally intense benchmarks, which include ray tracing and constraint solving.[101] They unanimously reported that Chrome performed much faster than all competitors against which it had been tested, including Safari (for Windows), Firefox 3.0, Internet Explorer 7, Opera, and Internet Explorer 8.[102][103][104][105][106][107] However in more recent independent tests of JavaScript performance, Chrome has been scoring just behind Opera's Presto engine since it was updated in version 10.5.[108]

On September 3, 2008, Mozilla responded by stating that their own TraceMonkey JavaScript engine (then in beta), was faster than Chrome's V8 engine in some tests.[109][110][111] John Resig, Mozilla's JavaScript evangelist, further commented on the performance of different browsers on Google's own suite, commenting on Chrome's "decimating" (sic) of the other browsers, but he questioned whether Google's suite was representative of real programs. He stated that Firefox 3.0 performed poorly on recursion-intensive benchmarks, such as those of Google, because the Mozilla team had not implemented recursion-tracing yet.[112]

Two weeks after Chrome's launch, the WebKit team announced a new JavaScript engine, SquirrelFish Extreme,[113] citing a 36% speed improvement over Chrome's V8 engine.[114][115][116]

Chrome uses DNS prefetching to speed up website lookups, as do Firefox[117] and Safari.[118] This feature is available in Internet Explorer as an extension, and in Opera as a UserScript.

Chrome utilizes the faster SPDY protocol designed to augment HTTP[119][120] when communicating with Google services, such as Google Search, Gmail, Chrome sync and when serving Google's ads. Google acknowledges that the use of SPDY is enabled in the communication between Chrome and Google's SSL-enabled servers.[121]
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Stability

A multi-process architecture is implemented in Chrome[122] where, by default, a separate process is allocated to each site instance and plugin. This procedure is termed process isolation,[123] and it prevents tasks from interfering with each other, raising security and stability. An attacker successfully gaining access to one application gains access to no others,[124] and failure in one instance results in a Sad Tab screen of death, similar to the well-known Sad Mac, but only one tab crashes instead of the whole application. This strategy exacts a fixed per-process cost up front, but results in less memory bloat overall as fragmentation is confined to each instance and no longer needs further memory allocations.[125] This architecture is being adopted in upcoming versions of Safari[126] and Firefox.[127] Thus, in the near future most common browsers will use a multi-process architecture.

Chrome includes a process management utility called Task Manager which lets users see what sites and plugins are using the most memory, downloading the most bytes and overusing the CPU and provides the ability to terminate them.[16]
[edit]
User interface

By default, the main user interface includes back, forward, refresh/cancel and menu buttons. A home button is not shown by default, but can be added through the preferences menu to take the user to the new tab page or a custom home page.

Tabs are the main component of Chrome's user interface and as such, have been moved to the top of the window rather than below the controls. This subtle change contrasts with many existing tabbed browsers which are based on windows and contain tabs. Tabs, with their state, can be transferred seamlessly between window containers by dragging. Each tab has its own set of controls, including the Omnibox.[16]

The Omnibox is the URL box at the top of each tab, which combines the functions of both the address bar and search box. If a user enters the URL of a site previously searched from, Chrome allows pressing Tab to search the site again directly from the Omnibox. When a user starts typing in the Omnibox, Chrome provides suggestions for previously visited sites (based on the URL or in-page text), popular websites (not necessarily visited before – powered by Google Suggest), and popular searches. Although Google Suggest can be turned off, suggestions based on previously visited sites cannot be turned off. Chrome will also autocomplete the URLs of sites visited often.[16] If a user types several keywords into the Omnibox and press enter, Chrome will conduct the search using the default search engine.

When Google Chrome is not maximized, the tab bar appears directly under the title bar. When maximized, the tabs become flush with the top of the titlebar. Like other browsers, it has a full-screen mode that hides the operating system's interface as well as the browser chrome.

One of Chrome's differentiating features is the New Tab Page, which can replace the browser home page and is displayed when a new tab is created. Originally, this showed thumbnails of the nine most visited web sites, along with frequent searches, recent bookmarks, and recently closed tabs; similar to Internet Explorer and Firefox with Google Toolbar 6, or Opera's Speed Dial.[16] In Google Chrome 2.0, the New Tab Page was updated to allow users to hide thumbnails they did not want to appear.[128]

Starting in version 3.0, the New Tab Page was revamped to display thumbnails of the eight most visited web sites. The thumbnails could be rearranged, pinned, and removed. Alternatively, a list of text links could be displayed instead of thumbnails. It also features a "Recently closed" bar that shows recently closed tabs and a "tips" section that displays hints and tricks for using the browser.[129]


Google Chrome logos. Top: 3D motif from project start until March 2011. Bottom: 2D motif from March 2011 until present.

Chrome includes a bookmark manager that can be opened from a menu. Adding the command-line option: --bookmark-menu adds a bookmarks button to the right of the Omnibox that can be used in place of the bookmarks bar.[130] As of 2009, this function was unavailable on the Linux and Mac platforms.[131]

Popup windows are associated with the tab they came from and will not appear outside the tab unless the user explicitly drags them out.[16]

Google Chrome's preferences page has four parts: Basic, Personal Stuff, Under the Hood, and, as of Chrome 15, a Downloads part. The Basic part includes options for the home page, search engine, and default browser. The Personal Stuff part lets users configure synchronization, saved passwords, form autofill, browsing data, and themes. The Under the Hood part allows changing network, privacy, download, and security settings. The Downloads part was a separate page at one time showing previous and active downloads but as of Chrome 15 is incorporated into Preferences.

Like Firefox, Chrome does not have a status bar, but displays loading activity and hover-over information via a status bubble that pops up at the bottom left of the relevant page, excluding hovering over links in image maps.

For web developers, Chrome features an element inspector similar to the one in Firebug.[117]

As part of Google's April Fools' Day jokes, a special build of Chrome was released on April 1, 2009 with the added feature of being able to render pages in anaglyph 3D.[132]

Chrome has special URLs that load application-specific pages instead of websites or files on disk. Chrome also has a built-in ability to enable experimental features. Originally called about:labs, the address was changed to about:flags to make it less obvious to casual users.[133][134]

In March 2011, Google introduced a new simplified logo to replace the previous 3D logo that had been used since the project's inception. Google designer Steve Rura explained the company reasoning for the change, "Since Chrome is all about making your web experience as easy and clutter-free as possible, we refreshed the Chrome icon to better represent these sentiments. A simpler icon embodies the Chrome spirit – to make the web quicker, lighter, and easier for all."[135]
[edit]
Desktop shortcuts and apps

Chrome allows users to make local desktop shortcuts that open web applications in the browser. The browser, when opened in this way, contains none of the regular interface except for the title bar, so as not to "interrupt anything the user is trying to do". This allows web applications to run alongside local software (similar to Mozilla Prism and Fluid).[16]

This feature, according to Google, will be enhanced with the Chrome Web Store, a one-stop web-based web applications directory which opened in December 2010.[136][137]
[edit]
Chrome Web Store
Main article: Chrome Web Store

Announced on December 7, 2010, the Chrome Web Store allows users to install web applications as extensions to the browser, although most of these function simply as links to popular web pages and/or games, but some of the apps like Springpad do provide extra features like offline access. The themes and extensions have also been tightly integrated into the new store, allowing users to search the entire catalog of Chrome extras.[138] The Chrome Web Store now acts as an App Store for Chromebooks.

Criticism of the idea came quickly. Ryan Paul of Ars Technica wrote on December 9, 2010: "The way that users consume applications in the desktop and mobile world is fundamentally different than they (sic) way that they do it on the Web—where paywalls are often reviled and there is little distinction between content and software. In such an environment, does the application store model make any sense? We are not convinced...Aside from gaming, the idea of an application store in a Web browser—where installation is little more than bookmarking—seems counterintuitive and leaves us with the impression that the entire exercise is a solution in search of a problem."[138]

The Chrome Web Store was opened on February 11, 2011 with the stable, non-beta, release of Google Chrome 9.0.597.98.[139]
[edit]
Aero peek capability

Google has included aero peek capability for each tab on Windows 7. This has not been added by default but can be user enabled,[140] resulting in a displayed thumbnail image of the tab. This will create similar functioning to that which is already included in IE 8, Firefox and other browsers.

Negative responses from beta users on the inefficiency of aero peek tabs implementation in Chrome led Google to exclude this as a default function.[141]
[edit]
Extensions

On September 9, 2009, Google enabled extensions by default on Chrome's Dev channel, and provided several sample extensions for testing.[142] In December, the Google Chrome extension gallery beta began with over 300 extensions.[27][143]

Along with Google Chrome 4.0, the extension gallery was officially launched on January 25, 2010, containing over 1500 extensions.[144]

Google became leaders in the field of Search engine optimization and have even published an SEO Starter Guide[145] which provides valuable information on how to optimize your site in the Google era. Matt Cutts who works for the Search Quality group in Google, specializing in search engine optimization issues, is well known in the SEO community for enforcing the Google Webmaster Guidelines and advising the public on how to get better website visibility in Google.[146] Thanks to Google's cooperation with the SEO industry, Google Chrome became a valuable browser for developers in the SEO business who developed many SEO extensions for Google Chrome,[147] Chrome web store also enables many SEO tools.

As of February 4, 2011, the extension gallery featured over 11500 extensions,[148] including official extensions from The Independent,[149] CEOP,[150] Transport for London,[151] Cricinfo,[152] WOT: Web of Trust[153] and FIFA.[154]

On October 2011, the Chrome webstore aka Extension gallery received a major upgrade, along with new extensions and better organization.[155]

Many Chrome extensions, once installed, have access to your data. According to the Chrome Web Store Help, there are three levels of permissions that an app or extension may request:
High Alert - "plug-ins can do almost anything, in or outside of your browser. For example, they could use your webcam, or they could read your personal files."
Medium Alert - "This item can read every page that you visit -- your bank, your web email, your Facebook page, and so on." And, "Besides seeing all your pages, this item could use your credentials (cookies) to request or modify your data from websites."
Low Alert - "This item can read data that you copy into your operating system clipboard, which might include sensitive or private information." Among other things.

Many seemingly simple extensions, such Google's own Screen Capture Tool, require High Alert permissions.
[edit]
Themes

Starting with Google Chrome 3.0, users can install themes to alter the appearance of the browser.[156] Many free third-party themes are provided in an online gallery,[157] accessible through a "Get themes" button in Chrome's options.[158]
[edit]
Automatic web page translation

Starting with Google Chrome 4.1 the application added a built-in translation bar using Google Translate. Translation is currently available for 52 languages.[159]
[edit]
Release channels and updates

On January 8, 2009 Google introduced a new release system with three distinct channels: Stable, Beta, and Developer preview (called the "Dev" channel). Before this change there were only two channels: Beta and Developer preview. All previous Developer channel users were moved to the Beta channel. The reason given by Google is that the Developer channel builds are less stable and polished than those that Developer channel users were getting during Google Chrome's Beta period. The stable channel will be updated with features and fixes once they have been thoroughly tested in the Beta channel, and the Beta channel will be updated roughly monthly with stable and complete features from the Developer channel. The Developer channel is where ideas get tested (and sometimes fail) and can be very unstable at times.[160][161] On July 22, 2010 Google announced it will ramp up the speed it will release new stable versions; they will shorten the release cycles from quarterly to 6 weeks.[162] The faster release cycle brought a fourth channel: the "Canary" release; the name refers to using canaries in coal mines, so if a change "kills" Chrome Canary, they will block it from the developer build. Canary will be "the most bleeding-edge official version of Chrome and somewhat of a mix between Chrome dev and the Chromium snapshot builds". Canary releases run side-by-side with any other channel; it is not linked to the other Google Chrome installation and can therefore run different synchronization profiles, themes, and browser preferences.[163] It cannot be set as the default browser. Canary was Windows-only at first, a Mac OS X version was released on May 3, 2011.[164]

Chrome automatically keeps itself up to date. The details differ by platform. On Windows, it uses Google Updater, and autoupdate can be controlled via Group Policy,[165] or users can download a standalone version that does not autoupdate.[166][167] On Mac, it uses Google Update Service, and autoupdate can be controlled via the Mac OS X "defaults" system.[168] On Linux, it lets the system's normal package management system supply the updates.

Google uses its Courgette algorithm to provide the binary difference of the user's current version in relation to the new version that's about to be automatically updated to. These tiny updates are well suited to minor security fixes and allow Google to push new versions of Chrome to users quickly, thereby reducing the window of vulnerability of newly discovered security flaws.[169]
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Usage tracking

Chrome sends details about its usage to Google through both optional and non-optional user tracking mechanisms.[170]
Tracking methodsMethod[171] Information sent When Optional?
Installation Randomly generated token included in installer. Used to measure success rate of Google Chrome once at installation.[172]
On installation No
RLZ identifier[173] Encoded string, according to Google, contains non-identifying information how Chrome was downloaded and its install week, and is used to measure promotional campaigns.[172] Google provides the source code to decode this string.[41] On Google search query
On first launch and first use of address bar[172] Partial[note 2][172]
clientID[174] Unique identifier along with logs of usage metrics and crashes. Unknown Yes[175]
Suggest[174] Text typed into the address bar While typing Yes
Page not found Text typed into the address bar Upon receiving "Server not found" response Yes
Bug tracker Details about crashes and failures Unknown Yes[175]
Google Updater Details about Chrome version Unknown Yes


Some of the tracking mechanisms can be optionally enabled and disabled through the installation interface[176] and through the browser's options dialog.[174] Unofficial builds, such as SRWare Iron and ChromePlus, seek to remove these features from the browser altogether.[171] The RLZ feature is not included in the Chromium browser either.[41]

In March 2010, Google devised a new method to collect installation statistics: the unique ID token included with Chrome is now only used for the first connection that Google Update makes to its server. This sole remaining non-optional user tracking mechanism is removed following the server ping.[177]
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System requirements

The recommended requirements for optimal performance of Chrome are:[178]
Windows: XP Service Pack 2+ / Vista / 7, Intel Pentium 4 or later, 100 MB hard disk, 128 MB memory
Mac OS X: 10.5.6 or later, Intel (not PPC), 100 MB hard disk, 128 MB memory
Linux: Ubuntu 8.04 or later / Debian 5 / OpenSuse 11.1 , Intel Pentium 3 / Athlon 64 or later, 100 MB hard disk, 128 MB memory
[edit]
64-bit builds

As of 2011, 64-bit builds are available for Linux, with only 32-bit available for Mac OS X and Windows.[179][180]
[edit]
Reception
Further information: Usage share of web browsers and Browser wars


Usage share of web browsers according to StatCounter, Chrome was 23.16% in August 2011.[2]

In 2008, The Daily Telegraph's Matthew Moore summarises the verdict of early reviewers: "Google Chrome is attractive, fast and has some impressive new features, but may not—yet—be a threat to its Microsoft rival."[181]

Initially, Microsoft reportedly played down the threat from Chrome and predicted that most people will embrace Internet Explorer 8. Opera Software said that "Chrome will strengthen the Web as the biggest application platform in the world".[182] But by February 25, 2010, BusinessWeek had reported that "For the first time in years, energy and resources are being poured into browsers, the ubiquitous programs for accessing content on the Web. Credit for this trend—a boon to consumers—goes to two parties. The first is Google, whose big plans for the Chrome browser have shaken Microsoft out of its competitive torpor and forced the software giant to pay fresh attention to its own browser, Internet Explorer. Microsoft all but ceased efforts to enhance IE after it triumphed in the last browser war, sending Netscape to its doom. Now it's back in gear."[183] Mozilla said that Chrome's introduction into the web browser market comes as "no real surprise", that "Chrome is not aimed at competing with Firefox", and furthermore that it should not affect Google's revenue relationship with Mozilla.[184][185]
Chrome's design bridges the gap between desktop and so-called "cloud computing." At the touch of a button, Chrome lets you make a desktop, Start menu, or QuickLaunch shortcut to any Web page or Web application, blurring the line between what's online and what's inside your PC. For example, I created a desktop shortcut for Google Maps. When you create a shortcut for a Web application, Chrome strips away all of the toolbars and tabs from the window, leaving you with something that feels much more like a desktop application than like a Web application or page.
—PC World[186]

According to StatCounter, Chrome was the most used web browser in Argentina, Chile, Uruguay, Philippines, Malaysia, Pakistan, Mauritania, Tunisia, Albania, Republic of Macedonia, Moldova, Jamaica and Armenia in July 2011.[2]

Due to a faulty virus definition update on September 30, 2011, Microsoft Security Essentials incorrectly identified Google Chrome as malware and began deleting it from user's systems.[187][188][189][190]
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User tracking

Concern about Chrome's optional usage collection and tracking have been noted in several publications.[191][192] On September 2, 2008, a CNET news item[193] 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. The passage in question was inherited from the general Google terms of service.[194] On the same day, Google responded to this criticism by stating that the language used was borrowed from other products, and removed the passage in question from the Terms of Service.[195] Google noted that this change would "apply retroactively to all users who have downloaded Google Chrome".[196] There was subsequent concern and confusion about whether and what information the program communicates back to Google. The company stated that usage metrics are only sent when users opt in by checking the option "help make Google Chrome better by automatically sending usage statistics and crash reports to Google" when the browser is installed.[197]

The optional suggestion service included in Google Chrome has been criticized because it provides the information typed into the Omnibox to the search provider before the user even hits return. This allows the search engine to provide URL suggestions, but also provides them with web usage information tied to an IP address. The feature can be selected off in the preferences-under the hood-privacy box.[198]
[edit]
Do Not Track

In April 2011, Google was criticized for not signing onto the Do Not Track feature for Chrome that is being incorporated in most other modern web browsers, including Firefox, Internet Explorer, Safari, and Opera. Critics pointed out that a new patent Google was granted in April 2011, for greatly enhanced user tracking through web advertising, will provide much more detailed information on user behavior and that do not track will hurt Google's ability to exploit this. Software reviewer Kurt Bakke of Conceivably Tech wrote: "Google said that it intends charge [sic] advertisers based on click-through rates, certain user activities and a pay-for-performance model. The entire patent seems to fit Google's recent claims that Chrome is critical for Google to maintain search dominance through its Chrome web browser and Chrome OS and was described as a tool to lock users to Google's search engine and – ultimately – its advertising services. So, how likely is it that Google will follow the do-not-track trend? Not very likely." Mozilla developer Asa Dotzler noted: "It seems pretty obvious to me that the Chrome team is bowing to pressure from Google's advertising business and that's a real shame. I had hoped they'd demonstrate a bit more independence than that."[199][200][201]

Google argued that the technology is useless at the present time, as advertisers are not required to obey the user's tracking preference and as it is still unclear on what constitutes tracking (as opposed to storing statistical data or user preferences). As an alternative, Google offers an extension called "Keep My Opt-Outs", which permanently bars ad companies from installing cookies on the user's computer.[202]

The reaction to this extension was mixed. Paul Thurrott of Windows IT Pro called the extension "much, much closer to what I've been asking for—i.e. something that just works and doesn't require the user to figure anything out—than the IE or Firefox solutions" while lamenting the fact that the extension is not included as part of the browser itself.[203]
[edit]
Bundling practices

On Windows, Chrome comes bundled with the installers of various other applications such as the Adobe Flash Player plug-in (when installing it for Firefox, Opera, or Safari)[204] and Skype. In the case of Skype, the installer makes Chrome the default browser unless the user explicitly opts out.[205][verification needed] This has since changed.[