Google Chrome

Google Chrome is a freeware web browser made by Google. It builds on parts from other open source software, including WebKit and Mozilla Firefox. 
The name comes from the graphical user interface frame, or "chrome", of web browsers. The open source project behind Google Chrome is known as Chromium.

The first version was a beta for Microsoft Windows was released on 2 September 2008. macOS and Linux versions were released in December 2009.

Announcement 
The release announcement was going to be made on 3 September 2008, and a comic by Scott McCloud was to be sent to journalists and bloggers explaining the features of and reasons for the new browser. Copies that were for Europe were shipped early and German blogger Philipp Lenssen of Google Blogoscoped made a scanned copy of the 38-page comic available on his website after receiving it on 1 September 2008. Google then made the comic available on Google Books and their website and referenced it on its official blog along with an explanation for the early release. As of September 2, 2008, Google has a link to Google Chrome on their main page.

Design

Security 
Blacklists
Chrome downloads updates of two blacklists (one for phishing and one for malware) and warns users when they try 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". In the process of maintaining these blacklists, Google also notifies the owners of listed sites who may not be aware of the presence of the harmful software.

Sandboxing
Each tab in Chrome is sandboxed to "prevent malware from installing itself" or "using what happens in one tab to affect what happens in another". Following the principle of least privilege, each process is stripped of its rights and can compute but can't write files or read from sensitive areas (e.g. documents, desktop), this is similar to "Protected Mode" that is used by Internet Explorer 7 on Windows Vista. The Sandbox Team is said to have "taken this existing process boundary and made it into a jail"; for example, malicious software running in one tab is unable to sniff credit card numbers, interact with the mouse or tell "Windows to run an executable on the start-up" and will be terminated when the tab is closed. 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.

Plugins
Plugins such as Adobe Flash Player are typically not standardised and as such cannot be sandboxed like tabs. These often need to 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.

Incognito
Chrome includes an Incognito mode (similar to Safari's Private Browsing and Internet Explorer 8's InPrivate) which "lets you browse the web in complete privacy because it doesn’t record any of your activity" and discards cookies. When enabled for a window "nothing that occurs in that window is ever logged on your computer."

Speed 
JavaScript
The Javascript virtual machine was considered a sufficiently important project to be split off (like Adobe/Mozilla's Tamarin) and handled by a dedicated team in Denmark. Existing implementations were designed "for small programs, where the performance and interactivity of the system weren't that important" but web applications like Gmail "are using the web browser to the fullest when it comes to DOM manipulations and Javascript". The resulting V8 JavaScript engine was designed for speed and introduces new features with that in mind such as hidden class transitions, dynamic code generation, and precise garbage collection. Tests by Google show that V8 is about twice as fast as Firefox 3 and the Safari 4 beta.

User interface 
The main user interface includes back, forward, refresh, bookmark, go and cancel options similar to Safari browser, while the settings location looks like Internet Explorer 7/8. The minimize, maximize and close window buttons are based on Windows Vista
Gears
Chrome includes Gears which adds developer features that may or may not become web standards, typically relating to the building of web applications (including offline support).

New Tab Page
Chrome replaces the browser home page which is displayed when a new tab is created with a New Tab Page. This shows thumbnails of the eight most visited websites along with the sites most often searched, recent bookmarks, and recently closed tabs. This concept appeared first with Opera's Speed Dial.

Omnibox
The Omnibox is the URL box at the top of each tab, based on the one in Opera. It includes autocomplete functionality but will only autocomplete URLs that were manually entered (rather than all links), search suggestions, top pages (previously visited), popular pages (unvisited), and text search over history. Search engines can also be captured by the browser when used via the native user interface by pressing Tab.

Popups
Popup windows "are scoped to the tab they came from" and will not appear outside the tab unless the user explicitly drags them out. It is not clear whether they also run in their own process.

Rendering engine
At first, Chrome used the WebKit browser engine on advice from the Android. Since version 28, Chrome has used its own fork, or a version of WebKit called Blink. This is to allow Google to change Blink to suit Chrome's needs explicitly by removing things that Chrome doesn't need. The IOS version of Chrome still uses Blink due to IOS' requirements.

Tabs
Tabs are the primary component of Chrome's user interface and as such has been moved to the top of the window rather than below the controls (similar to Opera). This subtle change is in contrast to many existing tabbed browsers which are based on windows containing tabs. Tabs (including their state) can be seamlessly transferred between window containers by dragging. Each tab has its own set of controls, including the Omnibox URL box.

Standards

The first release of Google Chrome Beta (Build 1583) did not pass the Acid3 test; it scored 77/100 and does not render the image correctly. It passed the Acid2 test initially, but failed upon resizing. From version 4 onward, Google Chrome has passed the Acid1, 2, and 3 tests.

Webapps
Webapps can be launched in their own streamlined window without the Omnibox URL box and browser toolbar. This limits the browser chrome so as not to "interrupt anything the user is trying to do", allowing web applications to run alongside local software (similar to Mozilla Prism, Adobe AIR and Fluid).

Notes

References

Other websites 
  
 Chromium project page at Google Code
 Google Chrome features
 Official Google Blog article of Google Chrome
 Google Chrome Help 

Web browsers
Google