Comment by mdaniel

If you haven't seen it, there's also https://addons.mozilla.org/en-US/firefox/addon/temporary-con... (https://github.com/stoically/temporary-containers MIT) when you don't care about the containers but do care that their browsing context is isolated. The screenshot even shows the handy "delete temporary container 15 minutes after the last tab closes")

Actually, sorry, it seems to be https://addons.mozilla.org/en-US/firefox/addon/temporary-con... and https://github.com/GodKratos/temporary-containers) based solely on the language present in the add-on and commit history