In Windows I use, beside the main Firefox installation, one or even two "Firefox clones" for different purposes (specifically oriented addons and configurations, light configuration without addons, configuration for a different user, etc).
It's like profiles except it works for all of your applications.
Even the newbest of newbies can learn to click their name on a login screen.
There's nothing wrong with using multiple browsers if that's what you want to do (the whole point of Linux is that you can do what you want).
I am honestly stunned by the need you feel for entirely different browsers, while wanting them to be exactly alike.
Could you elaborate on a scenario in which this is needed?
I believe there is absolutely no need to use different identical entities for that in most cases.
I just mean, create a separate (system-level) user account for each user.
is a browser that is identical (based on Mozilla Firefox) or very similar and has large/full support for FF extensions, configuration, profiles. It has the merit of keeping the pace with FF 4+ (in contrast with Swiftweasel, for example.)] Edit after using multiple accounts: after testing for a while this solution that has prevailed here (was most up-voted) of using multiple accounts I have to say that it may involve certain problems in cases where other separate customizations/advanced uses are implemented.
(For example, using scripts to search internet for selected text may Edit considering the definitive answer: although answers proposing the use of multiple accounts were most voted, I will prefer an answer that proposes a separate browser, for two reasons: 1.
that is what the question asks for in the first place, and 2.
multiple accounts may involve some problems, like those mentioned above.