LDAP modules
From OpenCms Wiki
Lightweight Directory Access Protocol (Wikipedia entry)
The Alkacon OCEE Server Enhancement Package includes the Alkacon OpenCms Enterprise Extensions LDAP connector (screenshots).
Qbizm technologies have an LDAP module.
Sysium have an LDAP module.
There is also an open source ldap module maintained at sf.net, which additionally supports the SSO solution called Central Authentication Service (CAS). For the CAS Part see also CASifying OpenCms