所有平台：Mozilla推出了最新版本的Firefox3测试版，供测试人员和不耐烦的升级人员使用。Firefox3 Beta 4的改进包括更好的下载管理器、更智能的位置栏自动完成、更快的性能（Moz说，使用谷歌应用程序的速度是谷歌应用程序的两倍）、更好的内存处理，以及Mac、Windows和Linux用户使用新图标和工具栏时更加自然的外观和感觉。跳转之后，查看发行说明中的Beta 4亮点。

• New Download Manager: the revised download manager makes it much easier to locate downloaded files, and you can see and search on the name of the website where a file came from. Your active downloads and time remaining are always shown in the status bar as your files download.
• Full page zoom: from the View menu and via keyboard shortcuts, the new zooming feature lets you zoom in and out of entire pages, scaling the layout, text and images, or optionally only the text size. Your settings will be remembered whenever you return to the site.
• Integration with Vista: Firefox now has Vista-specific ic***, and uses native user interface widgets in the browser and in web forms.
• Integration with the Mac: the new Firefox theme makes toolbars, ic***, and other user interface elements look like a native OS X application. Firefox also uses OS X widgets and spell-checker in web forms and supports Growl for notificati*** of completed downloads and available updates. A combined back and forward control make it even easier to move between web pages.
• Integration with Linux: Firefox's default ic***, butt***, and menu styles now use the native GTK theme.
• Location bar & auto-complete: type in all or part of the title, tag or address of a page to see a list of matches from your history and bookmarks; a new display makes it easier to scan through the matching results and find that page you're looking for. Results are returned according to their frecency (a combination of frequency and recency of visits to that page) ensuring that you're seeing the most relevant matches. An adaptive learning algorithm further tunes the results to your patterns!
• Speed: improvements to our JavaScript engine as well as profile guided optimizati*** have resulted in significant improvements in performance. Compared to Firefox 2, web applicati*** like Google Mail and Zoho Office run twice as fast in Firefox 3 Beta 4, and the popular SunSpider test from Apple shows improvements over previous releases.
• Memory usage: Several new technologies work together to reduce the amount of memory used by Firefox 3 Beta 4 over a web browsing session. Memory cycles are broken and collected by an automated cycle collector, a new memory allocator reduces fragmentation, hundreds of leaks have been fixed, and caching strategies have been tuned.

Firefox3Beta4是测试人员的免费下载；这是一个测试版，所以请期待bug和奇怪之处，以及并非所有扩展都能使用它的可能性(这里有一个让您的扩展在Firefox3（测试版）中工作的变通方法。

下载Firefox 3 Beta 4[Mozilla]Firefox 3 Beta 4发行说明[Mozilla]Firefox 3 Beta 4评论[Mozilla链接]