I am trying to create a website that would contain 2-3 subdomains. The reason I want it to include subdomains is because the website is split up into several distinct parts, and each part requires its own theme and plugins.
Is there some way I can have users register for one site, and either 1) be automatically registered for the other subdomains or, preferably, 2) link their accounts to share names/info when they create an account on another subdomain?
The ideal would be to have something that operates exactly like SE, just on Wordpress. When you create an account on a new SE site, it automatically syncs up your account with your existing one. That's what I want.
How can I achieve this result?
A plugin would be extremely desirable, but is not necessary.