Here are some articles and blog posts about Apache CXF Fediz.
General
Fediz 1.1 introduces Federation across Security Domains (Part 1) (2013)
Fediz 1.1 introduces Federation across Security Domains (Part 2) (2013)
Understanding WS-Federation - Passive Requestor Profile (2014)
Plugins
IdP
Understanding Spring Web-Flow in Apache Fediz - Part 1 (2016)
Understanding Spring Web-Flow in Apache Fediz - Part 2 (2016)
Apache Fediz with Client Certificate Authentication (X.509) (2016)
OpenId Connect
Fediz with OpenID Connect Support and WS-Federation Bridge (1/2) (2015)
Fediz with OpenID Connect Support and WS-Federation Bridge (2/2) (2015)