From FusionForge Wiki

Provides delegated authentication to external OpenID providers. (https://fusionforge.org/tracker/index.php?func=detail&aid=113&group_id=6&atid=114)

NOT READY FOR PRODUCTION USE

Available on trunk (in https://fusionforge.org/scm/viewvc.php/trunk/src/plugins/authopenid/?root=fusionforge)

See its README for more details : https://fusionforge.org/scm/viewvc.php/*checkout*/trunk/src/plugins/authopenid/README?root=fusionforge