Firefox probably supported profiles before Chrome even existed. It always saved my life back in the days when you reinstalled the OS and you could just backup/copy over the entire directory of the profile.

Personally I edit the Firefox shortcut to add -p at the end of the target to get the profile manager showing up every time I launch.

I also use this when I spend a few weeks on a different machine at work: create a new profile, synchronize it with my account, then when I leave I nuke the entire profile.

You can use the profile manager. There is a way to do it from the graphical user interface (see the sibling comment), though I just run Firefox using firefox -p

Maybe set a different theme / persona on each profile.

If you want separate extensions as well, then goto about:profiles.

If you want cookie separation, check out Multi Account Containers.

Firefox supports multiple profiles: https://support.mozilla.org/en-US/kb/profile-manager-create-...

You need the containers extension. It's better than Chrome profiles.

Or see below https://news.ycombinator.com/item?id=21911697