Firefox 56 was recently released with new  features and security improvements

https://www.mozilla.org/en-US/security/known-vulnerabilities/firefox/#firefox56

  • Launched Firefox Screenshots, a feature that lets users take, save, and share screenshots without leaving the browser
  • Added support for address form autofill (en-US only)
  • Updated Preferences
    • Added search tool so users can find a specific setting quickly
    • Reorganized preferences so users can more easily scan settings
    • Rewrote descriptions so users can better understand choices and how they affect browsing
    • Revised data collection choices so they align with updated Privacy Notice and data collection strategy
  • Media opened in a background tab will not play until the tab is selected
  • Improved Send Tabs feature of Sync for iOS and Android, and Send Tabs can be discovered even by users without a Firefox Account