Starting today, you can download Firefox 4 Beta 1 for Windows, Mac OS X and Linux. Released a week past its end-of-June deadline, this new iteration of the browser is still shaky in some areas, but mostly stable enough for regular use.

The biggest improvement between Firefox 3 versions and the newest download is speed. In order to compete with blazing-fast releases of Google’s Chrome (which has stolen some of Mozilla’s market share), Safari and even Opera, Firefox has had to turbocharge its page load times.

Early reports find that Firefox 4 easily keeps up with these browsers and should rival Microsoft’s Internet Explorer 9 when it becomes available before the end of 2010. Mozilla says the final version of the new browser should be even faster.

This beta version represents a major shift in appearance for Firefox. For Windows users, tabs will now appear above the URL text box. This fairly radical change will be rolling out in future versions for Mac and Linux. This seems to be a direct attempt to style Firefox more closely to Google Chrome. Also in this direction, Firefox 4 incorporates drop-down menus of applications and bookmarks in the upper left-hand corner of the window.

Other interface changes include the combination of the stop and reload buttons and the ability to search for open tabs from the location bar.

Today’s beta release provides more support for CSS 3 and HTML5, and greater protection against buggy plugins crashing the whole browser. Mozilla also revamped its Jetpack SDK, allowing third-party developers to build new, lighter add-ons. The company says that even more changes are coming to the add-on development process.

Security is also being bumped up in this newer version, with options built in to prevent websites from looking into people’s browsing histories. The product’s roadmap also includes an updated security policy that should help stymie attacks.

Clearly, this Beta 1 version’s purpose is to collect suggestions for improvement. For all operating systems, Firefox 4 includes a Feedback button conveniently next to the search box. This feature lets you communicate what you liked and disliked about the release directly to Mozilla.

The company says its plan is to release a new beta version of the browser every two weeks.

VentureBeat's mission is to be a digital town square for technical decision-makers to gain knowledge about transformative enterprise technology and transact. Learn more about membership.