According to the changelog, since 2017.11.10 this is an empty package. The package seems to be have been retained for possible future use.
Closing as invalid as its installation will currently have no discernable affect to anyone installing Firefox. ** Changed in: firefox (Ubuntu) Status: Confirmed => Invalid -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to firefox in Ubuntu. https://bugs.launchpad.net/bugs/1274605 Title: Please demote xul-ext-ubufox from Firefox Recommends to Suggests Status in firefox package in Ubuntu: Invalid Bug description: xul-ext-ubufox is pulled in by Kubuntu at the moment but serves little to no advantages for us. We already have a notification helper that notifies the user for restarting the system or applications when the application has been upgraded, and we have a software notification helper for installing things like flash and other plugins. It would be useful for Kubuntu if xul-ext-ubufox was demoted from a Recommends to a Suggest and a flavor could then include it in their seeds. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/firefox/+bug/1274605/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp