Gluu has been one of the leading OpenID Connect Providers since interop 4 back in jan 2013 http://www.gluu.co/.fm8t and its still one of the best. Also, its not just about implementing all the endpoints... The Shibboleth IDP is an excellent and comprehensive implemenation, but its a bear to manage. OX also provides an easy to use Web UI that makes administration of the OP a breeze. Check out more at http://gluu.org or our wiki at http://ox.gluu.org !
