tresequis said

now that about:permissions is gone, how do we do all the things we used to do with that function?

With more difficulty, or in some cases, not at all.

But let's step back: what were you using the page for, and we can suggest where to find alternate dialog(s) for that information.

It used to be possible to see a list of all websites that had been granted permissions, to see what permissions had been granted, and to change those permissions .

How is this possible now without individually revisiting each website I ever previously visited?

It depends on the type of permission. That's what I was getting at.

There are dialogs opened by buttons on the Options page for permissions with customized/non-default settings:

• Content panel
  • Receive Notifications (if you set a permanent permission on the drop-down panel or in the Page Info dialog)
  • Open Popup windows

• Privacy panel
  • Set Cookies (select "Firefox will: Use custom settings for history" to see the Exceptions button)

• Security panel
  • Install Add-ons
  • Save Login

• Advanced panel, Network mini-tab
  • Offline Storage

I'm not aware of any built-in UI to view the following permissions for a site, other than the Page Info dialog:

• Plugins
• Location
• "Hide the Mouse Pointer" (what is this?)
• Load Images
• Camera
• Microphone

Maybe there's an add-on?