An incredible and very unique add-on that lets you have multiple isolated tabs/sessions at once in the same browser. Its best feature is the "restrict to site" so if let's say I put Google search inside a container and restricted it, everytime I wanna search something in the search bar it automatically opens up Google search in that container, isolated from every other tab and from my session, it opens Google search in an contained tab, Firefox within Firefox, Fireception. This is an essential add-on to have for anyone who cares about enhancing privacy. It's absolutely brilliant and you can't find it in any other browser.

Классный виджет.
Пользуюсь давно.
Косяков нЕ обнаружено за всё время))

This is Firefox's killer app

nice

really useful for web developement, much more convenient than starting multiple browsers in order to use to test a website with multiple accounts at the same time, also now you can sync containers between devices, making it easier to recreate your configuration on a new machine