随着Mozilla FireFox 55的到来，这款开源浏览器走入了一个全新的阶段，多线程的完善和正式引入让它的性能终于开始赶上，不过老旧的插件（如Flash）让浏览器在多线程运行时问题百出，在Firefox 55及以后的版本中，Mozilla将重点开始解决这些问题：比如，在55版本中，运行Flash控件将默认需要用户确认，并且不再允许从本地调用此类内容等。同时从55版本开始，Firefox将开始支持WebVR。

　　还有一个显而易见的更新是，搜索框和地址栏的关系变得更为紧密，您可以随时在地址栏中设定所输入关键词的搜索引擎并立即开始搜索，由此可见在不久的将来，独立的地址栏很有可能会被取消掉，搜索就像Chrome一样容易。

　　与此同时，“同步”特性也有了较大的增强，同步菜单中引入了一个进入Firefox同步中心的入口，在这里可以管理多个设备的Firefox同步。

　　New

　　Browsing sessions with a high number of tabs are now restored in an instant

　　Sidebar (bookmarks, history, synced tabs) can now be moved to the right edge of the window

　　Fine-tune your browser performance from the Preferences/Options page.

　　Makescreenshotsof webpages, and save them locally or upload them to the cloud. This feature will undergo A/B testing and will not be visible for some users.

　　Added Belarusian (be) locale

　　Assign custom shortcuts to Firefox menu items on OS X and macOS via System Preferences > Keyboard > Shortcuts

　　Simplify print jobs from within print preview

　　Use virtual reality devices with the web with theintroduction of WebVR

　　Search suggestions are now enabled by default for users who haven't explicitly opted-out

　　Search with any installed search engine directly from the location bar

　　Changed

　　Breaking profile changes - do not downgrade Firefox and use a profile that has been opened with Firefox 55+.

　　Windows stub installer is now streamlined for simpler installation. Users requiring advanced install options should usefull installers.

　　The Flash plugin is now click-to-activate by default and only allowed on http:// and https:// URL schemes. This change will be rolled out progressively and so will not be visible to all users immediately. For more information see theFirefox plugin roadmap

　　Modernized application update UI to be less intrusive and more aligned with the rest of the browser. Only users who have not restarted their browser 8 days after downloading an update or users who opted out of automatic updates will see this change.

　　Developer

　　Insecure sites can no longer access the Geolocation APIs to get access to your physical location

　　下载地址：https://ftp.mozilla.org/pub/firefox/releases/55.0/