A spec compliant, secure by default
Identity & Single Sign On for all earthlings and beyond
FIDO® Certified StrongKey FIDO Server (SKFS)
PHP strong authentication library, web interface & CLI, OATH certified
Zentyal is a Linux Small Business Server
apache cookie SSO mechanism.
An open source Identity & Access Management solution with AD-functions
PHP User Login and Management System based on Codeigniter
Two-factor authentication system
Deprecated project - see http://wordpress.org/extend/plugins/wpmuldap/