As previously announced, the Mozilla Project has released the final version of Firefox 4, the non-profit organisation's next generation web browser based on version 2.0 of the Gecko rendering platform (the Firefox 3.6 branch uses Gecko 1.9.2). This major update to the open source browser arrives after more than a year of development which included twelve beta releases and two release candidates, as well as a number of delays which postponed the arrival of the final version.
Firefox 4.0 includes a new "Tabs On Top"
layout across all platforms.Firefox 4 features a range of improvements and new features aimed at both users and developers alike. Once installed, Firefox 3.x users will immediately notice a new default 'tabs on top' layout across all platforms – on Windows 7 and Vista systems, the Firefox button also has a new look and support for Aero Glass has been added. With the new Tab Groups feature, also known as "Panorama", users can better manage their tabs by zooming out of the current browser tab to view a grid of thumbnail images for each open tab.
The stop and reload buttons have now been merged into a single button and the new Bookmarks Button has replaced the Bookmarks Toolbar. However, the developers note that users can "switch it (the Bookmarks Toolbar) back if you'd like". Additionally, users can now turn any browser tab into an "App Tab" by right-clicking on it and selecting "Make into App Tab" from the context menu. The Firefox Start Page (about:home) has also had its design refreshed.
Windows and Linux versions of Firefox 4.0 include a new
Firefox Button which contains all of the menu items.Under the hood improvements include a new JavaScript engine called JägerMonkey that is up to six times faster than that used by Firefox 3.6, and built-in Direct2D Hardware Acceleration for Windows 7 users which takes advantage of users' built-in graphics hardware – the GPU – on Windows systems using DirectX 10 to improve overall graphics performance; this allows the browser to load and display graphically intensive websites even faster. Some graphics rendering operations are now also hardware-accelerated using Direct3D 9 on Windows XP, Direct3D 10 on Windows 7 and Vista, and using OpenGL on Mac OS X. According to the developers, OpenGL support for Linux will arrive in a future release. On Mac OS X systems, the browser takes advantage of the Core Animation rendering model for plugins helping them to be drawn even faster and more efficiently.
Support for Firefox Sync is now built-into the
browser.Previously only available as an add-on, support for Firefox Sync is now built-in, allowing users to synchronise their bookmarks, passwords, preferences, forms, history and open tabs between Firefox installations running on different PCs or on mobile devices. The new Add-ons Manger (about:addons) now appears in a new browser tab instead of a separate window and some add-ons can be installed without restarting the browser, as well as automatically updated in the background.
The Firefox 4 Add-ons Manager now appears
in a new tab instead of a separate window.Thanks to an overhaul of the bookmarks and history code, startup and bookmarking performance have been improved and, with the Smart Location Bar, users can search for and switch to already open tabs. The developers have added support for the "Do Not Track" (DNT) header, an option that users can enable via a check box under the "Advanced" tab in Firefox's Preferences, to signal websites that the user wishes to opt-out of online behavioural tracking.
Changes For Developers
Changes aimed at web developers include support for new CSS Transitions which can be used to animate web content, an extension management API and per-compartment garbage collection, enabled by default, which reduces the amount of work that needs to be done during complex animations, making them smoother. Web typography has been improved via support for the OpenType font format. Web developers can now update the URL field without having to reload the page via the HTML History APIs and improvements have been made to APIs for JS-ctypes, a foreign function interface for extensions. An experimental API is also included to provide more efficient Javascript animations.
Developers will also notice several HTLM5 improvements as well, such as a new HTML5 parser, HTML5 video "buffered" property support and a new HTML5 Forms API for making web-based forms easier to implement and validate, as well as support for more HTML5 form controls. Other changes include native support for the WebM/VP8 video format in HTML5 <video> tags, introduced by Google as part of the WebM Project, and full support for WebGL – a JavaScript binding to OpenGL ES 2.0 with industry support from Google, Mozilla and Opera – has been added. Support has also been added for the new proposed Audio Data API.
Security enhancements include changes to CSS visited selectors to block web sites from being able to check a user's browsing history, support for the HSTS security protocol which lets sites tell the browser that they are only to be loaded over an SSL connection, and the addition of crash protection technology that isolates the processes in Firefox so that, when a crash occurs in a plug-in such as Adobe Flash, Apple QuickTime or Microsoft Silverlight, the whole browser will not crash.
An interactive online tour and video overview of some of the new features included in Firefox tour are provided on the Mozilla web site.
Further information about this major update, including a list of known issues, can be found in the release notes. Firefox 4.0 is available to download for Windows, Mac OS X and Linux in more than 80 languages from the project's web site. Alternatively, existing Firefox 3.x users can upgrade to the new versions, either by waiting for the automated update notification or by manually selecting "Check for updates" from the Help Menu.
Firefox binaries are released under the Mozilla Firefox End-User Software License Agreement and the source code is released under disjunctive tri-licensing that includes the Mozilla Public Licence, GPLv2 and LGPLv2.1.
