Mozilla has issued a new beta version of its Firefox browser - version 3.6 is now available to download in RC1 edition. Originally it was due for a mid-September release, but it slipped a little for reasons unknown.

The update includes version 1.9.2 of the Gecko engine - which Firefox uses to render web pages. That means that it should be a little speedier than before. Previous versions of the software have used version 1.9.1 and Mozilla says that it's possible that the browser will stop supporting 1.9.1 entirely with the release of Firefox 3.6.

Tab previews have appeared too - if you use ctrl-tab to switch between tabs (like you might use alt-tab to switch applications) then you'll get a preview window showing you which tabs you have open. Opera has this feature, but Chrome, Safari and Internet Explorer don't at the time of writing. There's also the option to get thumbnail previews on the taskbar for Windows 7 users.

The build is available to download right now. You can grab it from the Mozilla Foundation's FTP.