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.

Firefox 4 nightly releases now include built-in support for WebM video, based on Google’s open VP8 codec.

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.

Mozilla has renamed its Weave add-on to Firefox Sync. The plugin allows users to synchronise their password, bookmarks, history and tabs across multiple devices.

“We are excited to announce that the “Weave Sync” project from Mozilla Labs has officially graduated and is now being incorporated into the Firefox roadmap. “Weave Sync” is now named “Firefox Sync” and the service will become a feature of Firefox in an upcoming major release” announced Mozilla’s Ragavan Srinivasan.

The add-on for Firefox has already had over 1.4 million downloads, and is proving to be hugely popular. A similar feature is available in both Google Chrome and Opera.

Currently available in more than 15 languages, the Firefox Sync add-on can be downloaded from the Mozilla Add-ons website.

Native 64-bit builds of Firefox 4 Alpha for Windows are now appearing in the Firefox Nightly builds, and are expected to be released simultaneously when Firefox 4 ships.

Mac and Linux users have had 64-bit builds since early April, but there is still limited plug-in support, with most plug-ins falling back to 32-bit.

“This is still just a very very very early experimental build” noted Mozilla’s John O’Duinn. This means the browser may not behave as expected, and testers are advised to proceed with caution.

Eager testers can download 64-bit versions form the Firefox Nightly repository.

An article written by Richard MacManus from ReadWriteWeb suggests that Google Chrome’s battle is with Firefox, and not with Internet Explorer as many think.

They base this data on their Google Analytic data that is collected from their website, with users of the site being described as early adopters.

ReadWriteWeb data shows a big drop in Firefox users over the last 12 months, from 54% to 39%, while Chrome has enjoyed a jump from 7% to 18%, all while Internet Explorer usage has stayed constant at around 25%. These statistics make this theory sound plausible.

We can’t vouch for these figures in our own statistics, but it is interesting none the less. Market Share data from Net Applications shows that Firefox is still gaining share slowly, while Chrome is also growing, and Internet Explorer is on a one way slop down.

This would suggest that Firefox may be taking users away from Internet Explorer, but that older and more experienced Firefox users are taking the plunge to Google’s Chrome browser.

Either way, the entrance of Chrome into the market has surely stirred things up. Statistics over the next few months will be very interesting, with yesterdays release of Chrome for Mac and Linux.

Nightly releases of Firefox 4 now include Aero Glass for Windows Vista and Windows 7 users, with the feature still a work in progress.

“The feature was available first in early April but pulled back soon after to iron some important bugs” noted Mozilla Links Percy Cabello.

The above screenshot also showcases the ability to hide the menu bar, and move the tab bar above the location bar.

Keen users can test the new interface by downloading a copy of the latest Firefox nightly.

Mozilla Developer Rob Cambell has revealed that Firefox 4 is recieving a new DOM inspector, similar to what is found in other browsers, after it was removed from Firefox 3.

Currently, Firefox web developers use the Firebug add-on to achieve the same effect. Cambell has stated Mozilla is not out to “kill” the Firebug add-on, but to merely suplement it.

“Now every browser ships with a set of development tools. We didn’t feel that [the original] DOM Inspector was the right tool to include in the browser” wrote Cambell.

Early Firefox 4 builds that include the new, unfinished DOM inspector are available for download.

Mozilla has given a presentation discussing Firefox.Next, now officially known as Firefox 4, which bypasses the often talked about Firefox 3.7 version number.

New features set to make an appearance in the browser include:

• Speed – it will be “super-duper fast”
• Power – it will support “HTML 5 and beyond”
• Empowerment – users will be allowed to fully control their browser, its data, and their web experience
• Completely re-vamped user interface allowing layout customization and less chrome
• Improved stability and security
• Ability to install add-ons without restarting browser
• Better tools for developers
• 64-bit support
• Hardware acceleration
• Multitouch support

Currently, a Firefox 4 Beta is expected in June next month, with a possible final release planned for November, or Janurary if development slips past the November time-frame.

The full 50 minute presentation can be downloaded or watched online.

Along with the customisable tab bar, Firefox 4 also looks set to gain a new add-on manager, which is currently receiving a major overhaul.

The new add-on manager works in a browser tab, removing the need for a separate window completely. Along with the standard options for managing extensions, themes, and plugins is the ability to manage both installed languages and search engines.

Currently it is still very much a work in progress, with not all functions working as intended, with  icons and the interface still not final. Other features are still yet to be included, such as silent extension updates.

The new add-on manager is expected to start appearing in nightly builds of Firefox 4 soon.

Latest nightly builds of Firefox include a new customisable tab bar in the browser.

New builds allow buttons in tabs to be removed, saving valuable screen real estate for heavy tab users.

Previously this has been possible with third party add-ons, or by modifying the browsers own CSS files.

The tabs in this build also appear to be more rounded, as has been apparent in early interface mock ups for Firefox 4.

This is only the start of changes, with tab animations and aero glass still on their way for the upcoming browser.

Eager testers can view the new tab bar in action by downloading the latest nightly builds from the Mozilla FTP server.