On: Vivaldi 4.0

[BugWatch]

You can always use multiple ("specialized") instances of portable Firefox (with MultipleInstance=true in ini file). That's how I do it, and I've been using portable Firefox versions exclusively for 10+ years, I think.

[kyoji → BugWatch]

You are probably already aware, but there is an official extension that offers this functionality via sand-boxed tabs: https://addons.mozilla.org/en-US/firefox/addon/multi-account...

[Renaud → BugWatch]

Thanks for reminding me to try that again.

Last time was a couple of years ago and I had some trouble between instances but maybe I didn't do it right.