This server hosts the Yubico OpenID server.
You may authenticate via OpenID using your Yubikey. If you have a Yubikey, your OpenID URL is:
http://openid.yubico.com/user/?id=IDENTITY
Where you replace the string IDENTITY with the first 12 characters from your OTP's.
For example, if your key output the string 'vlrlcingbbkrtndu...' when you press the button, your OpenID URL is http://openid.yubico.com/user/?id=vlrlcingbbkr.
If you wish to link your Yubico dongle to another OpenID URL, you may manage your OpenID account.