Four months on from the high profile release of Firefox 3.0, Mozilla has announced the availability of Firefox 3.1 beta 1.

Changes include tweaks to web compatibility as well as enablement of new web features such as geolocation, video, offline application support and CSS improvements.

There's also a new tab-switching shortcut that shows previews of the tab you’re switching to and include TraceMonkey, Mozilla's "super-fast" JavaScript engine.

Mozilla remind users that it's not a fully completed product so there may be some rough edges visually and with the user experience, as usual the company asks for bugs and the like to be reported.

A second beta is scheduled for later this year to early next year, and the release of the product has been revealed for early 2009.