Google Chrome OS

300px Google Chrome OS with the new Aura window manager
Company / developer	Google Inc.
Programmed in	C, C++
OS family	Unix-like
Working state	Preinstalled on specific hardware (Chromebooks)
Update method	Rolling release
Package manager	Portage
Supported platforms	x86, ARM
Kernel type	Monolithic: Ubuntu[1] Linux kernel
Default user interface	Graphical interface based on the Google Chrome browser
License	Google Chrome OS Terms of Service[2]

Google Chrome OS is a Linux-based operating system designed by Google to work exclusively with web applications. Google announced the operating system on July 7, 2009 and made it an open source project, called Chromium OS, that November.^[3][4]

Unlike Chromium OS, which can be compiled from the downloaded source code, Chrome OS only ships on specific hardware from Google's manufacturing partners.^[5] The user interface takes a minimalist approach, resembling that of the Google Chrome web browser. Since Google Chrome OS is aimed at users who spend most of their computer time on the Web, the only application on the device is a browser incorporating a media player and a file manager.^{[4][6][7][8][9]}

The launch date for retail hardware featuring Chrome OS slipped after Google first announced the operating system: from an initial forecast date in late 2010 to June 15, 2011, when "Chromebooks" from Samsung (and then Acer in July) actually shipped.^{[10][11][12][13][14]}

History[link]

Google developers began coding the operating system in 2009, inspired by the growing popularity and lower power consumption of netbooks and the focus of these small laptops on Internet access. To ascertain marketing requirements for an operating system focused on netbook Web transactions, the company did not do the usual demographic research generally associated with a large software development project. Instead, engineers relied on more informal metrics, including monitoring the usage patterns of some 200 Chrome OS machines used by Google employees. Developers also noted their own usage patterns. Matthew Papakipos, former^[15] engineering director for the Chrome OS project, put three machines in his house and found himself logging in for brief sessions: to make a single search query or send a short email.^[6]

On November 19, 2009, Google released Chrome OS's source code as the Chromium OS project.^[4] As with other open source projects, developers are modifying code from Chromium OS and building their own versions, whereas Google Chrome OS code will only be supported by Google and its partners, and will only run on hardware designed for the purpose. Unlike Chromium OS, Chrome OS will be automatically updated to the latest version.^[16] InformationWeek reviewer Serdar Yegulalp wrote that Chrome OS will be a product, developed to "a level of polish and a degree of integration with its host hardware that Chromium OS does not have by default," whereas Chromium OS is a project, "a common baseline from which the finished work is derived" as well as a pool for derivative works. The product and project will be developed in parallel and borrow from each other.^[17]

At a November 19, 2009 news conference, Sundar Pichai, the Google vice president overseeing Chrome, demonstrated an early version of the operating system. He previewed a desktop which looked very similar to the Chrome browser, and in addition to the regular browser tabs also had application tabs, which take less space and can be pinned for easier access. At the conference, the operating system booted up in seven seconds, a time Google said it would work to reduce.^{[16][18][17][19]}

Also on November 19, 2009, Chris Kenyon, vice president of OEM services at Canonical Ltd announced that Canonical "is contributing engineering to Google [Chrome OS] under contract. In our discussions, Sundar Pichai and Linus Upson made it clear that they want, wherever feasible, to build on existing components and tools from the open source community without unnecessary re-invention. This clear focus should benefit a wide variety of existing projects and we welcome it."^[20]

On January 25, 2010, Google posted notes, images and a video of a conceptual design showing how a Chrome OS user interface might look on a tablet computer with a 5–10 inch screen. The design would include the same basic layout as on netbooks, but with a touch interface; an onscreen qwerty keyboard in different layouts; large, square icons placed above the tabs; and panels placed along the bottom edge that could be opened with an upward dragging motion.^[21][22] The posting was made two days before Apple announced the iPad tablet.^[23] On March 16, 2011, several changes to Chromium OS were made which indicate the development of a tablet version of Google Chrome OS.^[24]

In March 2010, Google indicated that consideration is being given to developing two versions of the operating system, a consumer version and an enterprise version.^[25]

Cr-48 prototype hardware[link]

The Cr-48 showing the setup screen seen when first booting up a Chromebook

At a December 7, 2010 press briefing, Google announced the Cr-48 laptop, a reference hardware design to test the Chrome OS operating system. It was named after Chromium-48, an unstable isotope of the metallic element known as Chromium^[26]. The laptop's design broke convention by replacing the caps lock key with a dedicated search key.^[27]

The Cr-48 was intended for testing only, not retail sales.^[28][29][30] Google addressed complaints that the operating system offers little functionality when the host device is not connected to the Internet. The company demonstrated an offline version of Google Docs running on Chrome OS and announced a 3G plan that would give Chrome OS users 100 MB of free data each month, with additional paid plans available from Verizon.^[13]

About 60,000 Cr-48s were distributed to testers and reviewers in early December 2010. Reviews of Chrome OS running on the Cr-48 in mid-December 2010 indicated that while the project held promise, it still had some distance to go before being ready for market.^[31][32]

On March 8, 2011, Google Product Management vice president Sundar Pichai stated that the last of the 60,000 Cr-48s had been shipped.^[33]

The Cr-48 notebooks have additional unused hardware components for implementation at a future date, including a Bluetooth 2.1 controller.^[34] The USB port only acts as a keyboard, mouse, ethernet adapter, or USB storage port and will not work as a printer port as there is no print stack on the operating system.^[35] Adding further hardware outside of the previously mentioned items will likely cause problems with the operating system's "self knowing" security model.^[36] Users are encouraged to use a secure service called Google Cloud Print to print to legacy printers connected to their desktop computers, or connect an HP ePrint, Kodak Hero, Kodak ESP, or Epson Connect printer to the Google Cloud Print service for a "cloud aware" printer connection.^[37]

Commercial hardware: Chromebooks[link]

Google initially named several development partners working on hardware for the operating system, with others named in the press, including Acer, Adobe, Asus, Freescale, Hewlett-Packard, Lenovo, Qualcomm, Texas Instruments, Toshiba,^[38] Intel,^[39] Samsung,^[40][41] and Dell.^[42]

On May 11, 2011 at its Google I/O developer conference, Google announced that the first two commercially available laptops incorporating Chrome OS would be manufactured by Acer Inc. and Samsung Electronics Co., with a retail price beginning at $349. The ship date was June 15 for the United States, the United Kingdom, France, Germany, Netherlands, Italy and Spain. The Chromebooks are sold in the United States through Amazon and Best Buy; internationally through "leading retailers". Google claimed an eight-second bootup time and eight-hour operation on one battery charge, and said that the chromebooks would require no virus protection. Models equipped with 3G connectivity receive 100 megabytes of wireless data per month, free for two years, with an additional gigabyte at $20 per month. Google is also working on a Chrome OS desktop machine.^[14][43][44]

Google also announced a monthly payment scheme for business and education customers at $28 and $20 per user, per month, respectively for a three-year contract, including replacements and upgrades.^[14]

Relationship to Android[link]

Google's successive introduction of the popular Android^[45] and Google Chrome OS has put the company behind two open source, client-based operating systems. Microsoft CEO Steve Ballmer accused Google of not being able to make up its mind.^[46] Google has suggested that the two operating systems address different markets, mobile and personal computing, which remain distinct despite the growing convergence of the devices. Co-founder Sergey Brin suggested that the two systems "will likely converge over time."^[47]

Steven Levy wrote that "the dissonance between the two systems was apparent" at the 2011 Google I/O developer conference. "Each day of the event featured a keynote devoted to one system followed by a press briefing where each team leader (Android's Andy Rubin and Chrome's Sundar Pichai) unconvincingly tried to explain why the systems weren't competitive. Co-founder Sergey Brin addressed the question by saying that owning two promising OS's was a problem that most companies would love to face".^[48]

Design[link]

Early in the project, Google put online many details of Chrome OS's design goals and direction.^[49] But the company has not followed up with a technical description of the completed operating system.

User interface[link]

Design goals for Google Chrome OS's user interface included using minimal screen space by combining applications and standard Web pages into a single tab strip, rather than separating the two. Designers considered a reduced window management scheme that would operate only in full-screen mode. Secondary tasks would be handled with "panels": floating windows that dock to the bottom of the screen for tasks like chat and music players. Split screens were also under consideration for viewing two pieces of content side-by-side. Google Chrome OS would follow the Chrome browser's practice of leveraging HTML5's offline modes, background processing, and notifications. Designers proposed using search and pinned tabs as a way to quickly locate and access applications.^[50]

New window manager and graphics engine[link]

On April 10, 2012, a new build of Chrome OS offered a choice between the original full-screen window interface and overlapping, re-sizable windows, such as found on Microsoft Windows and Apple's Mac OS X. The feature was implemented through the Ash window manager, which runs atop the Aura hardware-accelerated graphics engine. The April 2012 upgrade also included the ability to display smaller, overlapping browser windows, each with its own translucent tabs, browser tabs that can be "torn" and dragged to new positions or merged with another tab strip, and a mouse-enabled shortcut list across the bottom of the screen. One icon on the task bar shows a list of installed apps and bookmarks. Writing in CNET, Stephen Shankland argued that with overlapping windows, "Google is anchoring itself into the past" as both iOS and Microsoft's Metro interface are largely or entirely full-screen. Even so, "Chrome OS already is different enough that it's best to preserve any familiarity that can be preserved".^[51][52][53]

Architecture[link]

In preliminary design documents for the Chromium OS open source project, Google described a three-tier architecture: firmware, browser and window manager, and system-level software and userland services.^[54]

• The firmware contributes to fast boot time by not probing for hardware, such as floppy disk drives, that are no longer common on computers, especially netbooks. The firmware also contributes to security by verifying each step in the boot process and incorporating system recovery.^[54]
• System-level software includes the Linux kernel that has been patched to improve boot performance. Userland software has been trimmed to essentials, with management by Upstart, which can launch services in parallel, re-spawn crashed jobs, and defer services in the interest of faster booting.^[54]
• The window manager handles user interaction with multiple client windows much like other X Window managers.^[54]

Remote application access and virtual desktop access[link]

In June 2010, Google software engineer Gary Kačmarčík wrote that Chrome OS will access remote applications through a technology unofficially called "Chromoting," which would resemble Microsoft's Remote Desktop Connection.^[55] The name has since been changed to "remoting," and is "probably closer to running an application via Remote Desktop Services or by first connecting to a host machine by using RDP or VNC."^[56] Initial roll-outs of Chrome-OS laptops (Chromebooks) indicate an interest in enabling users to access virtual desktops.^[57][58]

Hardware support[link]

Google Chrome OS is initially intended for secondary devices like netbooks, not as a user's primary PC,^[18] and will run on hardware incorporating an x86 or ARM-based processor.^[7] While Chrome OS will support hard disk drives, Google has requested that its hardware partners use solid-state drives "for performance and reliability reasons"^[16] as well as the lower capacity requirements inherent in an operating system that accesses applications and most user data on remote servers. In November 2009 Matthew Papakipos, engineering director for the Google Chrome OS claimed that the Chrome OS consumes one-sixtieth as much drive space as Windows 7.^[59]

Integrated media player, file manager[link]

Google integrates a media player into both Chrome OS and the Chrome browser, enabling users to play back MP3s, view JPEGs, and handle other multimedia files while offline.^[55]

Chrome OS also includes an integrated file manager resembling those found on other operating systems, with the ability to display folders and their associated files, as well as preview and manage file contents using a variety of Web applications, including Google Docs and Box.net.^[60]

Printing[link]

Google Cloud Print is Google's proposed solution to help any application on any device to print on any printer. While the cloud provides virtually any connected device with information access, the task of "developing and maintaining print subsystems for every combination of hardware and operating system – from desktops to netbooks to mobile devices – simply isn't feasible."^[61][62] However, the cloud service would entail installing a piece of software, called a proxy, as part of Chrome OS. The proxy would register the printer with the service, manage the print jobs, provide the printer driver functionality, and give status alerts for each job.^[63]

Link handling[link]

Chrome OS was designed with the intention of having user documents and files stored on online servers. However, both Chrome OS and the Chrome browser have unresolved decisions regarding handling specific file types offline. For example, if a JPEG is opened from a local storage device, should a specific Web application be automatically opened to view it, and if so, which one? Similarly, if a user clicks on a .doc file, which website should open: Microsoft Office Live, Gview, or a previewing utility? The project director at that time, Matthew Papakipos, noted that Windows developers have faced the same fundamental problem: "Quicktime is fighting with Windows Media Player, which is fighting with Chrome." As the number of Web applications increases, the same problem arises.^[6]

Security[link]

In March 2010, Google software security engineer Will Drewry discussed Chrome OS security. Drewry described Chrome OS as a "hardened" operating system featuring auto-updating and sandbox features that will reduce malware exposure. He said that Chrome OS netbooks will be shipped with Trusted Platform Module, and include both a "trusted bootpath" and a physical switch under the battery compartment that actuates a developer mode. That mode drops some specialized security functions but increases developer flexibility. Drewry also emphasized that the open source nature of the operating system will contribute greatly to its security by allowing constant developer feedback.^[25]

At a December 2010 press conference, Google claimed that Chrome OS would be the most secure consumer operating system due in part to a verified boot ability, in which the initial boot code, stored in read-only memory, checks for system compromises.^[13]

Shell access[link]

Chrome OS includes the Chrome Shell, or "crosh", which offers minimal functionality such as ping and ssh, but no Bash-like shell abilities. In developer mode, a full-featured Bash shell can be opened via VT-2, and is also accessible via the crosh command "shell".^[64]

Reception[link]

Early on, Chrome OS was viewed as a competitor to Microsoft, both directly to Microsoft Windows and indirectly the company's word processing and spreadsheet applications—the latter through Chrome OS's reliance on cloud computing.^[65][66] But Chrome OS engineering director Matthew Papakipos argued that the two operating systems would not fully overlap in functionality because Chrome OS hosted is intended for netbooks, which lack the computational power to run a resource-intensive program like Photoshop.^[6]

Some observers claimed that other operating systems already fill the niche that Chrome OS is aiming for, with the added advantage of supporting native applications in addition to a browser. Tony Bradley of PC World wrote in November 2009: "We can already do most, if not all, of what Chrome OS promises to deliver. Using a Windows 7 or Linux-based netbook, users can simply not install anything but a web browser and connect to the vast array of Google products and other web-based services and applications. Netbooks have been successful at capturing the low-end PC market, and they provide a web-centric computing experience today. I am not sure why we should get excited that a year from now we'll be able to do the same thing, but locked into doing it from the fourth-place web browser."^[67]

A year later, Ryan Paul of Ars Technica came to similar conclusions. He wrote that Google's Cr-48 prototype "met the basic requirements for Web surfing, gaming, and personal productivity, but falls short for more intensive tasks." He praised Google's approach to security, but wondered whether mainstream computer users would accept an operating system whose only application is a browser. "In its current form, I think that the operating system could appeal to some niche audiences, like regular consumers users who really just need browsing or office productivity workers at companies that have gone Google or only use intranet apps. It's decidedly not a full-fledged alternative to the general purpose computing environments that currently ship on netbooks." Paul wrote that most of Chrome OS's advantages "can be found in other software environments without having to sacrifice native applications."^[31]

In reviewing the Cr-48 on December 29, 2010, Kurt Bakke of Conceivably Tech said: "in my household the Chromebook has turned into a family appliance and the most frequented computer in our household. Its 15 second startup time and dedicated Google user accounts made it the go-to device for quick searches, email as well as YouTube and Facebook activities. It has not turned into a device that can rival the appeal of any of our other notebooks – we have one gaming laptop, two mainstream notebooks and two netbooks in our household with five kids. The biggest complaint I heard was its lack of performance in Flash applications."^[68]

In ongoing testing, Wolfgang Gruener, also writing in Conceivably Tech, said that cloud computing at cellular data speeds is unacceptable and that the lack of offline ability turns the Cr-48 "into a useless brick" when not connected.^[69] "It's difficult to use the Chromebook as an everyday device and give up what you are used to on a Mac/Windows PC, while you surely enjoy the dedicated cloud computing capabilities occasionally."^[70] He praised a March 2011 update that included new trackpad control features, scrolling support, power improvements and a large number of bug fixes.^[71]

See also[link]

• Android (operating system)

References[link]

External links[link]

Wikimedia Commons has media related to: Chrome OS

• Release blog
• Google Chrome official blog
• Chromium OS project page
• Official Chrome OS notebooks page
• What is Google Chrome OS? on YouTube

Historical[link]

• Official announcement
• Google Chrome OS Live Webcast; November 19, 2009

Google Chrome

chrome
Google Chrome displaying its Wikipedia article
Developer(s)	Google Inc.
Initial release	September 2, 2008; 3 years ago  (2008-09-02)
Stable release	19.0.1084.52  (May 23, 2012; 34 days ago  (2012-05-23)) [+/−]
Preview release	20.0.1132.21 (Beta)  (May 30, 2012; 27 days ago  (2012-05-30)) 21.0.1155.2 (Dev)  (May 29, 2012; 28 days ago  (2012-05-29)) [+/−]
Written in	C++, Assembly, Python, JavaScript
Operating system	Android (4.0 and later) Linux Mac OS X (10.5 and later, Intel only) Windows (XP SP2 and later)
Engine	WebKit
Available in	50 languages
Development status	Active
Type	Web browser
License	Google Chrome Terms of Service[note 1]
Website	www.google.com/chrome

Google Chrome is a freeware 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. As of May 2012^[update], Google Chrome has approximately 33% worldwide usage share of web browsers, making it the most widely used web browser, according to Statcounter.^[1]

In September 2008, Google released a large portion of Chrome's source code as an open source project called Chromium.^[2][3]

History[link]

For six years, Google's Chief Executive Eric Schmidt opposed the development of 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".^[4]

Announcement[link]

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.^[5] Copies intended for Europe were shipped early and German blogger Philipp Lenssen of Google Blogoscoped^[6] made a scanned copy of the 38-page comic available on his website after receiving it on September 1, 2008.^[7] Google subsequently made the comic available on Google Books^[8] and mentioned it on their official blog along with an explanation for the early release.^[9]

Public release[link]

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.^[10] Chrome quickly gained about 1% market share.^{[9][11][12][13]} 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.^[14]

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.^[15] The first official Chrome Mac OS X and Linux developer previews^[16] were announced on June 4, 2009 with a blog post^[17] 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.^[18][19] Google Chrome 5.0, announced on May 25, 2010, was the first stable release to support all three platforms.^[20]

Chrome was one of the twelve browsers offered to European Economic Area users of Microsoft Windows in 2010.^[21]

Development[link]

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.^[22] 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.

Usage share of web browsers

Chrome uses the WebKit rendering engine to display web pages, on advice from the Android team.^[8] Chrome is tested internally 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.^[8]

Google created Gears for Chrome, which added features for web developers typically relating to the building of web applications, including offline support.^[8] However, Google phased out Gears in favor of HTML5.^[23]

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.^[24] 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.

On February 7, 2012, Google launched Google Chrome Beta for Android 4.0 (Ice Cream Sandwich) devices.^[25]

In March 2012 Google announced it was working on a version of Chrome for both the Metro and desktop versions of Windows 8.^[26]

Enterprise deployment[link]

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.^[27] 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^[28] – 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.^[29] Until version 18 the software is known not to be ready for Enterprise deployments with roaming profiles.^[30]

Chromium[link]

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 Mac OS X and Linux operating systems. The Google-authored portion of Chromium is released under the permissive BSD license.^[31] Other portions of the source code are subject to a variety of open source licenses.^[32] Chromium implements a similar feature set as 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.^[33][34] Chromium does not implement user RLZ tracking.^[35][36][37]

Release history[link]

Click "show" to expand the Release History table below.

Features[link]

Google Chrome aims to be secure, fast, simple^[83] and stable. There are extensive differences from its peers in Chrome's minimalistic user interface,^[8] which is atypical of modern web browsers.^[84] For example, Chrome does not render RSS feeds.^[85] 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.^[86][87] 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.^[88] 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.^[89]

Web standards support[link]

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 has passed all aspects of the Acid3 test.^[42]

On Ecma International's ECMAScript standards conformance Test 262^[90] (version ES5.1 of 2012-05-18), Chrome version 19.0.1084.52 scored 26/11570. The beta version 20.0.1132.17 scored 17/11570. The dev version 21.0.1145.0 scored 17/11570. For comparison, both Internet Explorer and Safari have scores of 600+. 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.^[91]

On the HTML5 test (April, 2012 – version 3.0),^[92] Chrome version 19.0.1084.52 scored 402 out of 500, with 13 bonus points. The beta version 20.0.1132.17 scored 413 out of 500, with 13 bonus points. The dev version 21.0.1145.0 scored 434 out of 500, with 13 bonus points.

Security[link]

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".^[8]

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.^[93] 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";^[94] 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.^[8] 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.^[95] On Linux sandboxing uses the seccomp mode.^[96][97]

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.^[8] Chrome supports the Netscape Plugin Application Programming Interface (NPAPI),^[98] but does not support the embedding of ActiveX controls.^[98] 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.^[99] Java applet support is available in Chrome with Java 6 update 12 and above.^[100] Support for Java under Mac OS X was provided by a Java Update released on May 18, 2010.^[101]

Security vulnerabilities[link]

No security vulnerabilities in Chrome had been successfully exploited in the three years of Pwn2Own from 2009–11.^[102] However, Chrome was the first browser to to be defeated at Pwn2Own 2012, by a French team who used zero day exploits to take complete control of a fully patched 64-bit Windows 7 PC using a booby-trapped website that overcame Chrome's sandboxing. It was also compromised twice at the 2012 CanSecWest Pwnium.^{[103][104][105]}

Google's official response to the vulnerabilities was delivered by Jason Kersey, who congratulated the researchers, noting "We also believe that both submissions are works of art and deserve wider sharing and recognition."^[106]

Malware blocking[link]

This section's factual accuracy may be compromised due to out-of-date information. Please help improve the article by updating it. There may be additional information on the talk page. (March 2012)

A study has shown that users are four times more likely to be tricked into downloading malware than be compromised by an exploit.^[107] Chrome 17 introduced download scanning protection.^[68] An older study reported Chrome 10 blocked only 13% of malicious URLs, the same as Safari and Firefox, behind Internet Explorer 9 which blocked 92%, and 100% with application-based filtering enabled. Exploits that install malware without the user being aware (for example clickjacking and drive-by downloads) were not included in this particular study.^[108][109]

Privacy[link]

Privacy mode[link]

The private browsing feature called Incognito mode prevents the browser from permanently storing any history information or cookies from the websites visited.^[110] Incognito mode is similar to the private browsing feature in other web browsers. Chrome was the second browser to implement this feature, after Safari.

Usage tracking[link]

Chrome sends details about its usage to Google through both optional and non-optional user tracking mechanisms.^[111]

Some of the tracking mechanisms can be optionally enabled and disabled through the installation interface^[117] and through the browser's options dialog.^[115] Unofficial builds, such as SRWare Iron and CoolNovo (previously known as ChromePlus), seek to remove these features from the browser altogether.^[112] The RLZ feature is not included in the Chromium browser either.^[37]

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.^[118]

Concern about Chrome's optional usage collection and tracking have been noted in several publications.^[119][120] On September 2, 2008, a CNET news item^[121] 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.^[122] 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.^[123] Google noted that this change would "apply retroactively to all users who have downloaded Google Chrome".^[124] 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.^[125]

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/bonnet-privacy box.^[126]

Do Not Track[link]

In February 2012, Google announced that Chrome will support Do Not Track by the end of 2012.^[127]

Speed[link]

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.^[8]

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.^[128] 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.^{[129][130][131][132][133][134]} 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.^[135]

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.^{[136][137][138]} 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.^[139]

Two weeks after Chrome's launch, the WebKit team announced a new JavaScript engine, SquirrelFish Extreme,^[140] citing a 36% speed improvement over Chrome's V8 engine.^{[141][142][143]}

Chrome uses DNS prefetching to speed up website lookups,^[144] as other browsers like Firefox,^[145] Safari^[146] Internet Explorer (called DNS Pre-resolution),^[147] and in Opera as a UserScript (not built-in).^[148]

Chrome utilizes the faster, SPDY protocol instead of HTTP^[149][150] 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.^[151]

Stability[link]

A multi-process architecture is implemented in Chrome^[152] where, by default, a separate process is allocated to each site instance and plugin. This procedure is termed process isolation,^[153] 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,^[154] 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.^[8] This architecture is being adopted in upcoming versions of Safari^[155] and Firefox.^[156]

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.^[8]

User interface[link]

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 Settings page to take the user to the new tab page or a custom home page.^[157]

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.^[8]

The Omnibox is a URL box that 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 Instant), and popular searches. Although Instant can be turned off, suggestions based on previously visited sites cannot be turned off. Chrome will also autocomplete the URLs of sites visited often.^[8] If a user types keywords into the Omnibox that don't match any previously visited websites and presses 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 title bar. Like other browsers, it has a full-screen mode that hides the operating system and browser interface.^{[citation needed]}

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, or Opera's Speed Dial.^[8] In Google Chrome 2.0, the New Tab Page was updated to allow users to hide thumbnails they did not want to appear.^[158]

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.^[159]

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.^[160] As of 2009^[update], this function was unavailable on the Linux and Mac platforms.^[161]

Popup windows are associated with the tab they came from and will not appear outside the tab unless the user explicitly drags them out.^[8]

Google Chrome's "Settings" page has four sections:

• Basic includes options for the home page, search engine, and default browser.^{[citation needed]}
• Personal Stuff lets users configure and manage their synchronized data, saved passwords, form autofill, browsing data, and themes.^{[citation needed]}
• Under the Hood allows changing network, privacy, download, and security settings.^{[citation needed]}
• Extensions, available since Chrome 15, allows users to install, remove, manage, and update Chrome's wide variety of browser extensions.^{[citation needed]}

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.^{[citation needed]}

For web developers, Chrome features an element inspector similar to the one in Firebug.^[144]

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.^[162][163]

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."^[56]

Desktop shortcuts and apps[link]

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).^[8]

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.^[164][165]

Chrome Web Store[link]

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.^[166]

The Chrome Web Store was opened on February 11, 2011 with the release of Google Chrome 9.0.^[167]

Extensions[link]

On September 9, 2009, Google enabled extensions by default on Chrome's Dev channel, and provided several sample extensions for testing.^[168] In December, the Google Chrome extension gallery beta began with over 300 extensions.^[19][169]

Along with Google Chrome 4.0, the extension gallery was officially launched on January 25, 2010, containing over 1500 extensions.^[170]

As of February 4, 2011, the extension gallery featured more than 11,500 extensions,^[171] including official extensions from The Independent,^[172] CEOP,^[173] Transport for London,^[174] Cricinfo,^[175] WOT: Web of Trust^[176] and FIFA.^[177]

Many Chrome extensions, once installed, have access to the user's data. There are three levels of permissions that an app or extension may request.^[178] There is no approval or moderation process for the extensions submitted to the Chrome Web Store.^{[citation needed]}

Themes[link]

Starting with Google Chrome 3.0, users can install themes to alter the appearance of the browser.^[179] Many free third-party themes are provided in an online gallery,^[180] accessible through a "Get themes" button in Chrome's options.^[181]

Automatic web page translation[link]

Starting with Google Chrome 4.1 the application added a built-in translation bar using Google Translate. Translation is currently available for 52 languages.^[182]

Release channels and updates[link]

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.^[183][184] 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.^[185] 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.^[186] 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.^[187]

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,^[188] or users can download a standalone version that does not autoupdate.^[189][190] On Mac, it uses Google Update Service, and autoupdate can be controlled via the Mac OS X "defaults" system.^[191] On Linux, it lets the system's normal package management system supply the updates.

Platforms[link]

Chrome is available for^[192]

• Windows: XP Service Pack 2+ / Vista / 7
• Mac OS X: 10.5.6 or later, Intel processors (not PowerPC)
• Linux: Ubuntu 8.04 or later / Debian 5 / OpenSuse 11.1 / Fedora

As of 2012, 32-bit and 64-bit builds are available for Linux, with only 32-bit builds available for Mac OS X and Windows.^[193][194]

Android version[link]

A beta version for Android 4.0 devices was launched on February 7, 2012, available for a limited number of countries from Google Play.^[195]

• Notable features: Synchronization with desktop Chrome to provide the same bookmarks and view the same browser tabs,^[196] Page pre-rendering,^[197] Hardware acceleration^[198]
• Many of the latest HTML5 features: almost all of the Web Platform’s features: GPU-accelerated canvas, including CSS 3D Transforms, CSS animations, SVG, WebSockets (including binary messages), Dedicated Workers; it has overflow scroll support, strong HTML5 video support, and new capabilities such as IndexedDB, WebWorkers, Application Cache and the File APIs, date and time pickers, parts of the Media Capture API.^[197][199] Also supports mobile oriented features such as Device Orientation and Geolocation.^[199]
• Mobile customisations: Swipe gesture tab switching,^[196] Link Preview allows zooming in on (multiple) links to ensure the desired one is clicked,^[196] Font size boosting to ensure readability regardless of the zoom level^[199]
• Missing from the desktop version: no sandboxed tabs,^[197][200] Safe Browsing,^[197] apps, or extensions^[198] Adobe Flash (now and in future),^[198] WebGL, Native Client^[198]
• Development changes: Remote debugging,^[197][201] part of the browser layer has been implemented in Java, communicating with the rest of the Chromium and WebKit code through Java Native Bindings.^[199] The code of Chrome for Android is a fork of the Chromium project. It is a priority to upstream most new and modified code to Chromium and WebKit to resolve the fork^[199]
• April 17, 2012 update included the availability to access in 31 additional languages and in all countries where Google Play is available. A desktop version of a website can also be requested as opposed to a mobile version. In addition, Android users can now add bookmarks to their Android home screens if they choose and decide which apps should handle links opened in Chrome.^[202]

Chrome OS[link]

Google Chrome is the basis of Google's Chrome OS operating system that ships on specific hardware from Google's manufacturing partners.^[203] The user interface has a minimalist design resembling the Google Chrome browser. Chrome OS is aimed at users who spend most of their computer time on the Web; the only applications on the devices are a browser incorporating a media player and a file manager.^{[204][205][206][207][208]}

Google announced Chrome OS on July 7, 2009.^[209]

Usage[link]

Usage share of web browsers according to StatCounter, Chrome was 31% in April 2012.^[210]

Most used web browser by country according to StatCounter:

  Internet Explorer

  Google Chrome

  Firefox

  Opera

In 2008, The Daily Telegraph's Matthew Moore summarizes 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."^[211]

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".^[212] 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."^[213] 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 would not affect Google's revenue relationship with Mozilla.^[214][215]

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^[216]

As of May 2012^[update], Chrome is the second most widely used browser, having overtaken Firefox in November 2011, with a 28.4% worldwide usage share of web browsers according to StatCounter.^[210][217]

Along with Safari and Mozilla Firefox, Chrome receives a weekend "bump", which boosts its marketshare by as much as three percentage points on weekends, at the expense of Internet Explorer.^[218]

It was reported by StatCounter, a web analytics company, that for the single day of Sunday, March 18, 2012 Chrome was the most used web browser in the world for the first time. Chrome secured 32.7% of the global web browsing on that day, while Internet Explorer followed closely behind with 32.5%.^[219]

From May 14–21, 2012 Google Chrome was responsible for more Internet traffic than Microsoft's Internet Explorer (for the first time), which long has held its spot as the most-used Web browser in the world.^[220] According to StatCounter, 31.88% of web traffic was generated by Chrome for a sustained period of one week and 31.47% by Internet Explorer. Though Chrome has topped Internet Explorer for single day's usage in the past, this is the first time it has led for one full week.^[221]

See also[link]

• Comparison of web browsers
• Criticism of Google
• Google Chrome Frame
• List of web browsers
• Timeline of web browsers
• Web browser history

Notes[link]

References[link]