Firefox 4

Mozilla Firefox 4

Firefox 4.0 onWindows 7.
Original author(s)	Mozilla Corporation
Developer(s)	Mozilla Corporation Mozilla Foundation
Initial release	March 22, 2011(2011-03-22)
Final release	4.0.1 / April 28, 2011(2011-04-28)
Repository	hg.mozilla.org/mozilla-central/
Written in	C++,JavaScript,CSS,XUL,XBL
Engine	Gecko
Operating system	Cross-platform
Size	11.9MB–Windows 26.8 MB –Mac OS X 13.2 MB –Linux
Available in	81 languages
Type	Web browser FTP client
License	MPL/GNU GPL/GNU LGPL
Website	firefox

Customized Firefox 4 onUbuntu

Mozilla Firefox 4is a version of theFirefoxweb browser,released on March 22, 2011.The firstbetawas made available on July 6, 2010; Release Candidate 2 (a base for the final version) was released on March 18, 2011.It was codenamedTumucumaque,and was Firefox's last large release cycle. The Mozilla team planned smaller and quicker releases following other browser vendors.The primary goals for this version included improvements in performance, standards support, and user interface.

There was one security update in April 2011 (4.0.1) and version 4 of the browser was made obsolete by the release ofFirefox 5in June 2011.

This marked a transition to giving much less weight to major version numbers, with 5 more major version numbers used by December of that year (5, 6, 7, 8, and 9), compared to 4 in nearly a decade of Firefox development (1, 2, 3, 4).

History

On October 13, 2006,Brendan Eich,Mozilla'sChief Technology Officer,wrote about the plans for "Mozilla 2", referring to the most comprehensive iteration since its creation of the overall platform on which Firefox and other Mozilla products run.Most of these objectives were incorporated into versions 3.0, 3.5, and 3.6. The largest changes, however, were deferred to Firefox 4.0.

In early May 2010, Mozilla's plans for Firefox 4.0 were officially detailed through a blog post by Mike Beltzner, Firefox director.

On May 25, 2011, the Firefox release manager wrote in an email "Firefox 5 will be the security update for Firefox 4," confirming Firefox 4 had entered its "end of life"phase where Mozilla will no longer issue updates. Mozilla continued to issue updates for Firefox 3.6 after 4's EOL declaration. Only one update (4.0.1) was issued for Firefox 4 during its lifetime. Many looking for a copy of this version 4 will be directed to version 6, which cannot run on PowerPC Macintoshes.

Features

Mozilla Firefox 4 includes many new features sinceversion 3.6.

User interface

Firefox 4 brought a newuser interface,with a new look designed to make it faster.Early mockups of the new interface onWindows,Mac OS X,andLinuxwere first made available in July 2009.

New features included improved "doorhanger" notifications, Firefox Panorama (a feature that lets the user visually group tabs),application tabs, a redesigned extension manager,Jetpackextensions support, integration withFirefox Sync,and support formultitouchdisplays.

Many changes were made to the user interface. By default, tabs were displayed on the top of the window, above thelocation barin the area formerly occupied by the window'stitle bar.The "stop", "reload", and "go" buttons were combined into a single button, placed on the right side of the address bar. The button changed dynamically, based on the current state of the page.

OnWindows VistaandWindows 7,themenu baris hidden by default with the most common actions moved to a new "Firefox" menu in the upper left-hand corner of the browser. Users can create persistent "app tabs", and customize thetabbar, as well as thebookmarkand navigation bars.Many of these features are similar to ones introduced byGoogle Chrome.

Engine

Firefox 4 is based on theGecko2.0 engine, which adds and improves support forHTML5,CSS3,WebM,andWebGL.Also, it includes a new JavaScript engine (JägerMonkey)and betterXPCOMAPIs.

JägerMonkeyis a newJavaScript enginedesigned to work alongside theTraceMonkeyengine introduced with Firefox 3.5. It improves performance by compiling "non-traceable" JavaScript into machine language for faster execution.

Firefox 4 is the first version of Firefox to drop native support of theGopher protocol;however, continued support is available through anadd-on.

Firefox 4 introduces an audioAPI,which provides a way to programmatically access or create audio data associated with an HTML5 audio element.It allows, for example, to visualize raw sound data, to use filters or to show the audio spectrum.

Firefox 4 no longer relies on the underlying OS for text layout/shaping. Instead, it usesHarfBuzz.This allows for smart OpenType layout/shaping which is consistent across different operating systems.

Performance

Firefox 4 has marked a major change in performance in comparison to former versions 3.6 and 3.5. The browser has made significant progress inSunspiderJavaScript tests as well as improvements in supporting HTML5.

Since Firefox 4.0 Beta 5,hardware accelerationof content is enabled by default on Windows Vista and Windows 7 machines usingDirect2D,on OS X using Quartz (basically CPU-only), and Linux usingXRender.Hardware acceleration of compositing is enabled by default on Windows XP, Windows Vista and Windows 7 machines usingDirect3D,OS X and Linux usingOpenGL.Using hardware acceleration allows the browser to tap into the computer'sgraphics processing unit,lifting the burden from theCPUand speeding up the display of web pages. Acceleration is only enabled for certain graphics hardware and drivers.

One of the performance optimizations was moving all application data into a single file, omni.jar, using a new file format based on theJava Archive format(previous versions used multiple files in the Java Archive format).For later versions the file was renamed omni.ja.

Privacy

Firefox 4 contains support for the"do not track" header,an emerging standard for Web privacy.The header signals the user's request to the web service that anyweb visitor trackingservice be disabled. In the future, this privacy request may become a legal requirement.

It also introduced the ability to deleteflash cookies,subjecting them to the same deletion rules as ordinaryHTTP cookies.

Development

Nightly builds were marked as 4.0a1pre between February and June 2008,but were renamed to 3.1a1pre afterwards.

Timeline

Release	Release date	Notes
Alpha 1	February 10, 2010.	Firefox 3.7 (Gecko 1.9.3)
Alpha 2	March 1, 2010
Alpha 3	March 17, 2010
Alpha 4	April 12, 2010
Alpha 5	June 16, 2010
Beta 1	July 6, 2010	The version number was changed to 4.0 (Gecko's 2.0)
Beta 2	July 27, 2010
Beta 3	August 11, 2010	Addition of "switch to tab", which allows searching for opened tabs using the address bar for quick switching.
Beta 4	August 24, 2010
Beta 5	September 7, 2010
Beta 6	September 14, 2010
Beta 7	November 10, 2010	Originally scheduled for the second half of September, but was delayed in order to stabilize the new JavaScript engine and finish the planned features
Beta 8	December 22, 2010
Beta 9	January 14, 2011
Beta 10	January 25, 2011
Beta 11	February 8, 2011	Ship eleventh revision of beta, with more betaN+ hardblockers fixed (14 betaN+ hardblockers not fixed)
Beta 12	February 25, 2011	Ship twelfth revision of beta, with all betaN+ hardblockers fixed. Mozilla senior engineering director Damon Sicore, urging his team totake this hilland push through to ship a release candidate by February 25.
RC 1	March 9, 2011	Complete work on all blocking 2.0:final + bugs, generate release candidates
RC 2	March 18, 2011	Two very small, very isolated fixes in order to better protect Firefox 4 users.
4.0	March 22, 2011	Release final version of Firefox 4.0.
4.0.1	April 28, 2011	Fixed several security and stability issues.

Reception

Market share overview According to StatCounter data July 2024

Browser % ofFx % of total Firefox 1 — — Firefox 2 — — Firefox 3 — — Firefox 4 — — Firefox 5–9 — — Firefox 10–16 0.73% 0.02% Firefox 17–23 — — Firefox 24–30 — — Firefox 31–37 — — Firefox 38–44 — — Firefox 45–51 — — Firefox 52–59 2.19% 0.06% Firefox 60–67 — — Firefox 68–77 — — Firefox 78–90 0.37% 0.01% Firefox 91–101 — — Firefox 102–114 — — Firefox 115 and 115 ESR 13.14% 0.36% Firefox 116 — — Firefox 117 — — Firefox 118 2.56% 0.07% Firefox 119 — — Firefox 120 0.37% 0.01% Firefox 121 0.37% 0.01% Firefox 122 — — Firefox 123 1.10% 0.03% Firefox 124 0.37% 0.01% Firefox 125 0.73% 0.02% Firefox 126 2.19% 0.06% Firefox 127 25.55% 0.70% Firefox 128 and 128 ESR 40.15% 1.10% Firefox 129 — — All variants 100% 2.74%

On 22 March 2011, and during the 24-hour launch period, Firefox 4 received 7.1 million downloads, as counted and verified by theMozilla Foundation.Before that date, 3 million people downloaded the second release candidate of the browser, which later became the final version.As a result, the new version of the browser received 10 million downloads on the first day.Notwithstanding, it fell behind the previous record established by the launch of Firefox 3 in 2008, which was 8 million. Second-day downloads for the browser were reported to be 8.75 million, but the lack of an official representative fromGuinnessto monitor the numbers, made the record attained byFirefox 3only unofficially been broken.

Usage share

See also:Usage share of web browsers

On the official launch date, the usage share for the Firefox 4 was 1.95%, which was 0.34% higher than the previous day according to analytics website StatCounter. As a comparison, the usage share for theInternet Explorer 9on March 22 was 0.87%,and it was released the prior week, on March 14. A potential factor on Firefox 4's higher usage share is that the latter supports bothWindows 2000andXP,two operating systems Internet Explorer 9 does not support.

Also, at launch, Mozilla prompted existing customers to upgrade their browsers to the newer version, something Microsoft hadn't applied to users of older versions of Internet Explorer.Instead, Microsoft prompted users to upgrade viaWindows Updateseveral weeks after launch.

On March 26, 2011, Firefox 4's usage share exceeded that of the 10-year-old and discontinued Internet Explorer 6 for the first time. Also on that date, the browser's usage share was higher than all versions ofSafari,Operaand older versions of Firefox with the exception ofFirefox 3.6.As a reference, Internet Explorer 9's usage share first exceeded that ofInternet Explorer 6on May 1, 2011 (48 days after release), and Internet Explorer 9 became the second most used version of Internet Explorer for the first time on May 22, 2011 (69 days after release).

According to StatCounter, Firefox 4 reached its usage share peak of 16.7% on June 19, 2011. After that date, it started to decline due to weekly trends and the release ofFirefox 5.

Migration issues

Expanded Firefox button showing the new arrangement of menus and commands

Firefox 4 represents a departure in user interface layout and behaviour from previous versions.Users face some issues negotiating these changes, some of which are not documented in the release notes.

Firefox button

The Firefox button groups the menus in Firefox 4. It is displayed by default on the Windows 7 and Windows Vista operating systems.It can be displayed on other operating systems by selecting "Toolbars" from the View menu and unchecking "Menu Bar". The Menu bar can be restored by selecting "Options" from the Firefox button menu and checking "Menu Bar". Certain menu items, such as "Page Info" and "Import" (for importing bookmarks and other browser data), are not available from the Firefox button menu but remain available from the Menu bar.The Menu bar can be displayed temporarily by pressing and releasing the Alt key.Selecting a Menu bar command or pressing the Alt key again dismisses the Menu bar.

Session data

A prompt to save the session (tabs and windows) was presented by default in Firefox 3, with the session restored on the next start if the user selected the "Save & Quit" option. In Firefox 4, all sessions are saved. On the next start, the session is available from the History menu.

This new feature, called on-demand session restore, overwrites the previous session on exit without prompting. The user can check whether there is a saved session at any time by viewing the History menu item "Restore Previous Session".If it is available (not greyed out) there is a restorable session available.

In beta 7 introduced new config option to limit the number of tabs loaded at once during session restore. This also made possible to lazy load tabs,the preferences option to switch this behavior appeared in version 8.

See also

• Firefox early version history

External links

• Official website
• Firefox Nightly Builds
• Firefox 4 video decoder architecture
• Rapid Release plans