Using Clients Single Sign-on

Using Clients Single Sign-on

  
Ok, so I have a multi-tanant app that goes into Universities, each of them have some method of SSO, that they want us to use.  I am looking for best use case approach to this.  LDAP, x.500, Shibboleth are some of the things I have heard :)
Erm,

doesn't it depend how the universities have done it?