Apache Fortress™ is a standards-based access management system, written in Java, that provides role-based access control, delegated administration and password policy services with LDAP.
Included are the following components:
Core - Java Access Management SDK
Realm - Java EE security for Apache Tomcat
Rest - HTTP protocol wrappers for the APIs
Web - HTML pages for the APIs
In short Fortress implements ANSI Role-Based Access Control (INCITS 359) and has a nice Web interface: