A lot of Firefox users don’t know about this feature and it has been estimated that only 0.01% of Firefox users actually use this feature. Panorama was introduced in Firefox 4 and this feature lets you organize tabs into groups.
Also know as Tab Groups, Panorama still exists in Firefox and can be accessed on Windows by pressing Ctrl+Shift+E. According to Firefox:
We’re removing panorama/tab groups/tabview, because it’s mostly unused (estimates around 0.01% of users, see bug 1210773 comment 6), because its quality is not exactly great, and because it incurs comparably (very) high costs in terms of maintenance.
Firefox initially planned to offer this feature as a plugin but the bug status has been set toResolved Wontfix. A developer has released an addon to replace this feature even before it’s totally gone:
This addon will only work starting from Firefox 45.0. If you’re trying to use it on Firefox 45 Nightly, you need to change xpinstall.signatures.required value false in about:config to install the add-on.
You shouldn’t use this addon along with the default Panorama feature. According to the developer:
Please do not open Panorama if you use this extension and Panorama is not yet removed from Firefox. If you have opened Panorama, you have to restart your browser to make this add-on work again since Panorama registers some event listeners that conflict with our code