One of the reasons I've been reluctant to go back to FF is the lack of support for users (that Chrome). I like to set up a Chrome user (effectively a new instance of the browser) for each project / client. Each gets ends up with its own password manager, history, bookmarks, etc.

Having users helps me silo things abd stay organized. I can also have multiple users' browsers open at the same time.

How can I replicate this with FF?