Question regarding common forum softwares but especially smf

[KingScorpio]

is it possible to create a forum where people can either do a social login

or a login with accounts from other smf?

[mdayonliner]

is it possible to create a forum where people can either do a social login

or a login with accounts from other smf?

I can not tell you smf but from common sense I can say if two forum located in two different server then I do not think it will really help. I guess for login authentication you need to communicate with browser's session variable. Same session variable is not gonna work for different server IMO.

It is completely possible to add social login feature for any forum even with smf. If smf currently do not have such feature then all you need to do is hire a developer who can do the job. 

[Talk merit]

You'd need to control the hosting for both accounts, and to provide access to the primary password file to the second forum.
You would need to modify the login routine as well of course.

[KingScorpio]

You'd need to control the hosting for both accounts, and to provide access to the primary password file to the second forum.
You would need to modify the login routine as well of course.

so is it possible to create somehow a forum which all users of this forum could use with the same accounts, and the forum has different theme looks different etc.

regards