Mozilla is adding a native Windows 10 Share experience to Firefox 64. This allows users to share web sites using a variety of applications that are installed in Windows 10. This is a nice feature to have in desktop browsers as it is so heavily used in the mobile counterparts. Mozilla also recently added the ability to display browser notifications directly in the Windows 10 action center to Firefox. This further shows that Mozilla aims to integrated Firefox into Windows 10 operating system rather than just being another installed app. The feature is available now in Firefox Nightly.
Source: https://www.bleepingcomputer.com/news/security/mozilla-adding-native-windows-10-share-support-to-firefox-64/