Drupal
(from wikipedia) Drupal is a free and open source modular framework and content management system (CMS) written in the programming language PHP. Drupal, like many modern CMSs, allows the system administrator to organize the content, customize the presentation, automate administrative tasks, and manage site visitors and contributors. Although there is a sophisticated programming interface, most tasks can be accomplished with little or no programming. Drupal is sometimes described as a "web application framework", as its capabilities extend from content management to enabling a wide range of services and transactions.
Drupal runs in many environments, including Windows, Mac OS X, Linux, FreeBSD, and any platform that supports either the Apache (version 1.3+), or IIS (version IIS5+) Web server and the PHP language (version 4.3.3+). Drupal requires a database such as MySQL or PostgreSQL to store content and settings.
Integration
A shibboleth 1.3 module exists for drupal - see the links.
Feide is working on a drupal module for simpleSAMLphp, which would enable SAML 2.0 and Shibboleth 1.3 integration. This is estimated to be ready March 2008.
OpenID support is built-in. Separate module before 6.x, and included in core >= 6.x.