What is pac4j ?
pac4j is an open source project : https://github.com/leleuj/pac4j.
It's a Profile & Authentication Client for Java. It targets all the protocols supporting the following mechanism :
It has a very simple and unified API to support these 4 protocols on client side :
It's available under the Apache 2 license.
If you have any question, please use the following mailing lists : https://groups.google.com/forum/?hl=en#!forum/pac4j-users or https://groups.google.com/forum/?hl=en#!forum/pac4j-dev.
What is cas-server-support-pac4j ?
Since CAS server 4.0, cas-server-support-pac4j is a new Maven module for the CAS server. It's based on the pac4j library and adds CAS/OpenID/OAuth client support to the CAS server : authentication can be delegated through a link on the login page to a CAS, OpenID or OAuth provider.
Before CAS server 4.0, the OAuth client support was in the cas-server-support-oauth module.