Google Chrome is a freeware web browser developed by Google that uses the WebKit layout engine until version 27 and, with the exception of its iOS releases, from version 28 and beyond the WebKit fork Blink. It was released as a beta version for Microsoft Windows on September 2, 2008, and as a stable public release on December 11, 2008. As of April 2013, according to StatCounter, Google Chrome has a 39% worldwide usage share of web browsers making it the most widely used web browser in the world.
In September 2008, Google released the majority of Chrome's source code as an open source project called Chromium, on which Chrome releases are still based.
Announcement
| Scott McCloud |
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. Copies intended for Europe were shipped early and German blogger Philipp Lenssen of Google Blogoscoped made a scanned copy of the 38 page comic available on his website after receiving it on September 1, 2008. Google subsequently made the comic available on Google Books and mentioned it on their official blog along with an explanation for the early release.
Public release
The browser was first publicly released for Microsoft Windows on
September 2, 2008 in 43 languages, officially a beta version.
On the same day, a CNET news item drew attention to a passage in the Terms of Service statement for the
initial beta release, which seemed to grant to Google a license to all
content transferred via the Chrome browser. This passage was inherited
from the general Google terms of service
Google responded to this criticism immediately by stating that the
language used was borrowed from other products, and removed this passage
from the Terms of Service.
Chrome quickly gained about 1% usage share.
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.
In early January 2009, CNET reported that Google planned to release versions of Chrome for OS X and Linux in the first half of the year. The first official Chrome OS X and Linux developer previews
were announced on June 4, 2009 with a blog post saying they were
missing many features and were intended for early feedback rather than
general use.
In
December 2009, Google released beta versions of Chrome for OS X and
Linux. Google Chrome 5.0, announced on May 25, 2010, was the first
stable release to support all three platforms.
Chrome was one of the twelve browsers offered to EEA users of Microsoft Windows in 2010
Development
Chrome was assembled from 25 different code libraries from Google, and a number of other open-source projects. The V8 JavaScript virtual machine was considered a sufficiently important project to be split off and handled by a separate teamin Denmark coordinated by Lars Bak at Aarhus.
According to Google, existing implementations were designed "for small
programs, where the performance and interactivity of the system weren't
that important", but web applications such as Gmail "are using the web browser to the fullest when it comes to DOM manipulations and JavaScript", and therefore would significantly benefit from a JavaScript engine that could work faster.
Chrome uses the Blink
rendering engine to display web pages. Based on WebKit2, Blink only
uses WebKit's "WebCore" components while substituting all other
components, such as its own multi-process architecture in place of
WebKit's native implementation.
Chrome is internally tested with unit testing, "automated user interface testing of scripted user actions", fuzz testing,
as well as WebKit's layout tests (99% of which Chrome is claimed to
have passed), and against commonly accessed websites inside the Google
index within 20–30 minutes.
Google created Gears
for Chrome, which added features for web developers typically relating
to the building of web applications, including offline support. However,
Google phased out Gears in favor of HTML5.
 |
| Mike Jazayeri |
On January 11, 2011 the Chrome product manager, Mike Jazayeri, announced that Chrome would remove H.264 video codec
support for its HTML5 player, citing the desire to bring Google Chrome
more in line with the currently available open codecs available in the
Chromium project, which Chrome is based on.Despite this, on November 6, 2012, Google released a version of Chrome on Windows which added hardware-accelerated H.264 video decoding.
On February 7, 2012, Google launched Google Chrome Beta for Android 4.0
devices. On many new devices with Android 4.1 and later preinstalled,
Chrome is the default browser.
On April 3, 2013, Google announced that it would fork WebCore to form its own layout engine known as Blink.
The aim of Blink will be to give Chrome's developers more freedom in
implementing its own changes to the engine, and to allow its codebase to
be trimmed of code that is unnecessary or unimplemented by Chrome
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