Mozilla已经将Firefox 54.0 Beta 5的安装文件放到了FTP，相比之前几个Beta版本，54版的改进明显变小，主要带来了下载面板中的信息显示部分的完善以及在书签列表中区分出移动设备添加的书签的特性，在性能上面似乎并没有发现有什么变化。
New
Clearer and more detailed information for download items in the download panel
Bookmarks created on mobile devices are now shown in "Mobile Bookmarks” folder in the drop down list from the toolbar and Bookmarks option in the menu bar in Desktop Firefox
Developer
Changes for web developers
Create your own custom devices in Responsive Device Mode
下载地址: