• OpenID : How’s it work? (http://openid.net/about.bml)
• OpenID : authentication protocol flow diagram (http://openid.net/pres/protocolflow-1.1.png)
• OpenIDEnabled : OpenID Protocol (http://www.openidenabled.com/openid/openid-protocol)
• OpenIDEnabled : How Does it Work? (http://www.openidenabled.com/openid/about-openid)

e claro…

• OpenID na Wikipedia (http://en.wikipedia.org/wiki/OpenID)