As a result, there are no new features in Beta 6. Fixed in this release is a rendering issue affecting Mac OS X users, and a stability issue causing crashes in Windows. More details on the update can be found in the release notes.

Firefox 4 Beta 6 is available in 39 languages, and can be downloaded from the Firefox Beta website.

The latest release is available in 39 languages, and now has support for the HSTS security protocol.

Windows users have hardware acceleration turned on by default, with a new Firefox menu also making it’s appearance for Vista and 7 users.

A more detailed list of changes can be read in the release notes. Current beta users will be prompted to update in the coming days, while new testers can download the beta from the Firefox Beta website.

Mozilla are still hard at work, today releasing Firefox 4 Beta 4 tot the public which is packed with several new features.

New in the latest release is Firefox Panorama, which lets you arrange and organise your tabs at the click of a mouse button.

Also new in this release is the inclusion of Firefox Sync, which syncs bookmarks, tabs, history and passwords between different computers you use. Previously this has been available as an add-on for Firefox, but as of now it is included directly with the browser.

Firefox 4 Beta 4 is available for Windows, Mac and Linux users right now. A full list of changes can be read in the release notes.

Mozilla is still busy at work, today releasing Firefox 4 Beta 3 to the public.

Beta 3 is now available in over 30 languages, 10 more than the previous beta. Also new in this release is multi-touch support for Windows 7 and new JavaScript values to experience faster and smoother graphics.

A full list of changes can be read in the release notes, and current Firefox 4 Beta testers will automatically receive the update in the coming days.

Firefox 4 Beta 3 can be downloaded from the Mozilla Firefox Beta website.

“For Firefox 4 minor updates will occur automatically.  Users can change the setting in Options > Advanced > Update.  We’ll only be using the major update dialog box for changes like 4 to 4.5 or 5″ wrote Mozilla’s Alex Faaborg.

The implementation will be slightly different to Chromes, with users still seeing the updating progress bar on load, but this is an implementation issue, which will hopefully be addressed in the future.

The aim of this of course is to keep users safe, and take away the hassle of users having to install security updates when prompted.

Auto-updates are expected to appear in Firefox 4 before it is final release to the public later this year.

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.

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.

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.

WebM support is included in Windows, Mac, and Linux Firefox nightly builds. Previously, WebM had been made available by special builds that were announced with the release of the WebM format.

Firefox Programmer Chirs Pearce has posted details on his blog for users wanting to build the browser themselves.

Eager testers can download Firefox 4 Alpha from the Firefox nightlies. Firefox 4 final is expected before the end of the year.