privacyIDEA is a management and authentication system for two factor authentication. You can use OTP tokens, OTP cards, SMS, Smartphone Apps to incorparte the second factor. It can even manage SSH keys and supports Offline OTP. The latest version can manage and enroll user certificates.
Its modular design makes it easily enhancable. It runs on Linux.
Applications and workflows can be connected to privacyIDEA hence enabling two factor authentication in your system logon, web...
Korreio is GUI to mail systems management based on LDAP, CYRUS and POSTFIX. Its has some integrated modules: a LDAP manager, Cyrus-IMAP Mailbox (cyradm replacement), Cyrus-IMAP Partition manager (report-like), Sieve manager, Postfix Queue manager.