- [cschiewek / devise_ldap_authenticatable]
- [ajrkerr / devise_active_directory_authenticatable]
- [nbudin / devise_cas_authenticatable]
- [rubycas / rubycas-server] - SSO authentication for web applications, implements the server-end of Jasig's CAS protocol.
- [socialcast / devise_oauth2_providable] - Rails3 engine integrating OAuth2 authentication with Devise