Among the new features in Firefox 8 is the addition of Twitter to the list of default search engines that users can access from the browser's toolbar. The new entry--which is available only in the Mac and Linux versions of the browser--makes searching for hash tags (#firefox, #browser, and such) on the microblogging site easier.

Another improvement: As a security precaution, Firefox 8 will warn you before any third-party add-on launches for the first time. That approach should keep you from being surprised by an unwanted applet's sudden appearance on the Firefox toolbar.

In this version of the browser, Mozilla has modified tabs in a couple of ways. In the Windows and Mac releases of the beta, you can configure the software so that it restores only the tabs you've selected; this tweak can improve startup times in cases when the browser has saved many tabs on exit. Tab animation is also improved, making it easier to "tear off" tabs and move them around.

Among the treats for developers in the beta is the use of Cross-Origin Resource Sharing for more secure loading of textures from other domains, plus another security improvement: prevention of the creation of plaintext WebSockets from an SSL page.

Improved HTML 5 support is included in the new offering too. Firefox 8 allows developers to add items to the program's right-click menu by using the HTML 5 markup language, as well as to add lots of video and audio elements to a website without dragging down performance.