CloudFoundry User Account and Authentication (UAA) Server
The Single Sign-On Multi-Factor portal for web apps
Cross-platform application monitoring and error tracking software
Identity management and federations integration
LDAP tools to support formerly NIS environments.
A Java-based LDAP API
PHP strong authentication library, web interface & CLI, OATH certified
An Elixir Authentication System for Plug-based Web Applications
A SigV4 authentication plugin for the open-source DataStax Java Driver
Zentyal is a Linux Small Business Server
apache cookie SSO mechanism.
Apache LDAP Directory Manager
Facebook authentication strategy for Passport and Node.js.
Mature LDAP, LDIF and DSML client with i18n support.
PHP User Login and Management System based on Codeigniter
phpbb Multiple domain Single Sign on with wordpress plugin