Mozilla has released Beta 2 of Firefox 4, which is now available in 24 languages.

The update includes many changes, including apps tab feature.

“There are some websites you visit many times throughout your day, such as your email, social networks, music or game sites. Now you can turn the websites you use most into App Tabs to easily find the ones you need” said a release from Mozilla.

Mac users now receive the new interface that was delivered to Windows users in Beta 1, and puts tabs on top by default.

There is also more support for CSS3 transitions, retained layers allowing for faster scrolling on complex websites, and changes to the XPCOM framework reducing the browser start up time.

A full list of changes can be read in the release notes. Firefox 4 Beta 2 can be downloaded from the Firefox Beta website.

Future versions of Firefox are to get a new tab organisation feature called Tab Candy. The feature, which resembles exposé from Mac OS X, allows users to easily group and organise tabs into groups.

“With one keystroke Tab Candy shows an overview of all tabs to allow you to quickly locate and switch between them. Tab Candy also lets you group tabs to organize your work flow. You can create a group for your vacation, work, recipes, games and social sites, however it makes sense to you to group tabs. When you switch to a grouped tab only the relevant tabs are shown in the tab bar, which helps you focus on what you want” wrote Mozilla’s Aza Raskin.

Available as an alpha build, Tab Candy is written solely with HTML, CSS and JavaScript, meaning there is no native code for any platform.

More details on the project can be found in the Mozilla Wiki, while an alpha preview can be downloaded form the Mozilla FTP.

The update fixes severe crashing bug which many users were seeing when they viewed pages containing plugins.

More details can be found in the release notes. The update will be pushed out to existing Firefox 3.6.x users in the coming days. New users can download the browser from the Firefox website.

A total of 14 security vulnerabilities have been patched, 4 of which are rated as moderate, 2 high, and 8 are of critical severity. A full list of changes can be read in the release notes.

Current Firefox 3.6.x users will receive the update  in the coming days,  while new users can download Firefox from the Firefox website.

Mozilla have released Firefox 4 Beta 1 to the public, after final beta 1 builds started to appear last week.

Firefox 4 has many changes over 3.6, and is based on Gecko 2.0 rendering engine. New in Firefox 4 include:

• Tabs on top for Windows by default  (Mac and Linux changes coming later)
• Menu bar replaced by Firefox button for Windows Vista and Windows 7 users
• New add-ons manager
• CSS transitions
• Native HD HTML5 WebM video support

A full list of changes can be found in the release notes. Firefox users can download Firefox 4 Beta 1 from the Firefox Beta website.

Mozilla has just passed a massive milestone, with its two billionth Firefox add-on being downloaded from its Add-ons for Firefox website.

“When we reached 1 billion Firefox Add-on downloads in November 2008, we thought it would take us less than 3 years to get to the next billion, and with your help, we’ve gotten to 2 billion in half that time! With more than 150 million add-ons in use every day, we know that the next billion add-on downloads will be here before we know it” wrote Julie Shin Choi, on behalf of the Firefox Add-ons Team.

Mozilla’s implementation of add-ons for Firefox is by far the best solution, giving add-on developers much more control and freedom compared to add-ons and extensions available for Chrome and Opera. This implementation is the key to why Firefox has so many users today.

Any Firefox users who are not using add-ons are really missing out, with add-ons available for just about everything you can think of, from download management, to social and communication, and even to web development.

Firefox add-ons are free, and are checked by Mozilla before they are released to the public. You can start browsing for add-ons on the Add-ons for Firefox website.

No change log has yet been released, and Mozilla will not announce the release until a final Beta release is ready. There are currently two bugs blocking build 2, which are expected to be fixed shortly. Currently the release is available for Windows, Mac, and Linux, with native 64-bit builds for Mac and Linux users.

Would-be-testers are warned that while more stable than the alpha releases, this build still has a lot of work to be done before it is ready to be used by the masses. As a result, some of your plugins may not work with this release.

More information on Firefox Beta 1′s release can be seen on the MozillaWiki. Firefox 4 Beta 1 Build 1 can be downloaded from the Mozilla FTP server.

Early builds of Firefox 4 are starting to show the browser new interface.

Part of the revamp includes moving tabs above the address bar by default, which isn’t something everyone is happy about. Thankfully, this can be changed easily by the user.

“This is a preference that users can change by right clicking on any of their toolbars.  Moving the default tab position is obviously a significant and to some extent controversial change to the Firefox UI, which is why we made the video above to help explain our rationale” explains Alex Faaborg, User Experience Design at Mozilla.

Firefox 4 Beta’s are expected in the next few weeks, with a final release before the end of 2010.

“Firefox 3.6.6 modifies the crash protection feature to increase the amount of time that plugins are allowed to be non-responsive before being terminated” said the Firefox 3.6.6 release notes.

Existing Firefox 3.6.4 users will receive the update in the coming days, or it can be downloaded manually from the Firefox website. The update is available for Windows, Mac and Linux users.

Mozilla has finally released Firefox 3.6.4, after weeks of testing. The new release includes the highly talked about out-of-process plugin support.

The move, aimed at increasing browser stability, moves Adobe Flash, Apple Quicktime and Microsoft Silverlight plugins into their own process. If one of these plugins crashes, the browser will no longer crash along with it. Instead users will be given the option to reload the plugin and its content.

Currently, out-of-process plugin support is only available for Windows and Linux, with Mac versions expected in the near future. Support for other plugins is said to be on its way in future Firefox releases.

This release also fixes several security issues, 4 of which are rated as critical. A full list of changes for this release can be read in the release notes.

Existing Firefox 3.6.x users will receive the update in the coming days, or it can be downloaded directly from the Firefox website.