How to decide which authentication to use in multitenant environment?

Question

I am designing one Multi tenant based CRM system, Where tenant will be identified by sub domain. But I am a bit confuse about the authentication system, which one to use. STS using some third party tool like thinktecture Or simple membership provided by Microsoft framework.

Answer 1

Identity Server 3 (Thinktecture) will be your best bet.

Simple Membership is a fair bit out of date... See Brock Allen's article Think twice about using MembershipProvider (and SimpleMembership) for a good argument against Simple Membership.