目前已进入测试版(beta)的Firefox 7比Firefox 4至6版执行效率更高，占用的存储少一半，而且可以协助网页开发人员创造更快更优良的网页或网站应用服务。

Firefox 7新增MemShrink技术，可以更有效率的管理存储，官方宣称可以降低20-50%的存储用量，这样同时可以减少使用存储分页，进而 降低软件卡死的频率。其中一个关键是强化JavaScript的管理，让浏览器同时及长期开启多个分页的时候，可以适时推出存储。

下载:Mozilla Firefox 7.0 Beta 5

The latest version of Firefox Beta has the following changes:

Drastically improved memory use
Added a new rendering backend to speed up Canvas operations on Windows systems
Bookmark and password changes now sync almost instantly when using Firefox Sync
Added support for text-overflow: ellipsis
Added support for the Web Timing specification
Added an opt-in system for users to send performance data back to Mozilla to improve future versions of Firefox. This can be enabled by installing an add-on
Fixed several stability issues
Please see the complete list of changes in this version. You may also be interested in the list of changes in the previous version.