Version 56.0, first offered to Release channel users on September 28, 2017
Today's release gives Firefox users a better experience with features like Firefox Screenshots, Send Tabs, and more control over the browser with an improved (and searchable) preferences section. It also includes incremental performance improvements that move us closer to our biggest release of the year, coming in November.
We'd like to extend a special thank you to all of the new Mozillians who contributed to this release of Firefox!
Launched Firefox Screenshots, a feature that lets users take, save, and share screenshots without leaving the browser
Startup crashes with 64-bit Firefox on Windows 7, for users of Lenovo's "OneKey Theater" software for IdeaPad laptops. To fix this crash, please re-install 32-bit Firefox. (bug 1369361)
Users running Firefox for Windows over a Remote Desktop Connection (RDP) may find that audio playback is disabled due to increased security restrictions. Learn how to mitigate this issue until it is corrected in an upcoming release.
Due to a bug in Mac OS X High Sierra, fullscreen mode has some issues (bug 1390125)