You can connect any application (written in any language or on any stack) to Auth0 and define its Connection, the method used to authenticate the users of that application:
• Custom credentials: username + passwords
• Social network logins: Google, Facebook, Twitter, and any OAuth2, OAuth1 or OpenID Connect provider
• Enterprise directories: LDAP, Google Apps, Office 365, ADFS, AD, SAML-P, WS-Federation, etc.
• Passwordless systems: TouchID, one time codes on SMS, or email